diff --git a/app/assets/javascripts/discourse-common/addon/lib/discourse-template-map.js b/app/assets/javascripts/discourse-common/addon/lib/discourse-template-map.js
new file mode 100644
index 0000000000..51ec2c6c3c
--- /dev/null
+++ b/app/assets/javascripts/discourse-common/addon/lib/discourse-template-map.js
@@ -0,0 +1,102 @@
+const pluginRegex = /^discourse\/plugins\/([^\/]+)\/(.*)$/;
+const themeRegex = /^discourse\/theme-([^\/]+)\/(.*)$/;
+
+function appendToCache(cache, key, value) {
+  let cachedValue = cache.get(key);
+  cachedValue ??= [];
+  cachedValue.push(value);
+  cache.set(key, cachedValue);
+}
+
+const NAMESPACES = ["discourse/", "wizard/", "admin/"];
+
+function isInRecognisedNamespace(moduleName) {
+  for (const ns of NAMESPACES) {
+    if (moduleName.startsWith(ns)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+function isTemplate(moduleName) {
+  return moduleName.includes("/templates/");
+}
+
+/**
+ * This class provides takes set of core/plugin/theme modules, finds the template modules,
+ * and makes an efficient lookup table for the resolver to use. It takes care of sourcing
+ * component/route templates from themes/plugins, and also handles template overrides.
+ */
+class DiscourseTemplateMap {
+  coreTemplates = new Map();
+  pluginTemplates = new Map();
+  themeTemplates = new Map();
+  prioritizedCaches = [
+    this.themeTemplates,
+    this.pluginTemplates,
+    this.coreTemplates,
+  ];
+
+  /**
+   * Reset the TemplateMap to use the supplied module names. It is expected that the list
+   * will be generated using `Object.keys(requirejs.entries)`.
+   */
+  setModuleNames(moduleNames) {
+    this.coreTemplates.clear();
+    this.pluginTemplates.clear();
+    this.themeTemplates.clear();
+    for (const moduleName of moduleNames) {
+      if (isInRecognisedNamespace(moduleName) && isTemplate(moduleName)) {
+        this.#add(moduleName);
+      }
+    }
+  }
+
+  #add(originalPath) {
+    let path = originalPath;
+
+    let pluginMatch, themeMatch, cache;
+    if ((pluginMatch = path.match(pluginRegex))) {
+      path = pluginMatch[2];
+      cache = this.pluginTemplates;
+    } else if ((themeMatch = path.match(themeRegex))) {
+      path = themeMatch[2];
+      cache = this.themeTemplates;
+    } else {
+      cache = this.coreTemplates;
+    }
+
+    path = path.replace(/^discourse\/templates\//, "");
+
+    appendToCache(cache, path, originalPath);
+  }
+
+  /**
+   * Resolve a template name to a module name, taking into account
+   * theme/plugin namespaces and overrides.
+   */
+  resolve(name) {
+    for (const cache of this.prioritizedCaches) {
+      const val = cache.get(name);
+      if (val) {
+        return val[val.length - 1];
+      }
+    }
+  }
+
+  /**
+   * List all available template keys, after theme/plugin namespaces have
+   * been stripped.
+   */
+  keys() {
+    const uniqueKeys = new Set([
+      ...this.coreTemplates.keys(),
+      ...this.pluginTemplates.keys(),
+      ...this.themeTemplates.keys(),
+    ]);
+    return [...uniqueKeys];
+  }
+}
+
+export default new DiscourseTemplateMap();
diff --git a/app/assets/javascripts/discourse-common/addon/lib/raw-templates.js b/app/assets/javascripts/discourse-common/addon/lib/raw-templates.js
index 2b88dfc82b..b979d7c8ff 100644
--- a/app/assets/javascripts/discourse-common/addon/lib/raw-templates.js
+++ b/app/assets/javascripts/discourse-common/addon/lib/raw-templates.js
@@ -32,11 +32,25 @@ export function findRawTemplate(name) {
 
 export function buildRawConnectorCache(findOutlets) {
   let result = {};
-  findOutlets(__DISCOURSE_RAW_TEMPLATES, (outletName, resource) => {
-    result[outletName] = result[outletName] || [];
-    result[outletName].push({
-      template: __DISCOURSE_RAW_TEMPLATES[resource],
-    });
-  });
+  findOutlets(
+    Object.keys(__DISCOURSE_RAW_TEMPLATES),
+    (outletName, resource) => {
+      result[outletName] ??= [];
+      result[outletName].push({
+        template: __DISCOURSE_RAW_TEMPLATES[resource],
+      });
+    }
+  );
   return result;
 }
+
+export function eagerLoadRawTemplateModules() {
+  for (const [key, value] of Object.entries(requirejs.entries)) {
+    if (
+      key.includes("/templates/") &&
+      value.deps.includes("discourse-common/lib/raw-templates")
+    ) {
+      require(key);
+    }
+  }
+}
diff --git a/app/assets/javascripts/discourse-common/addon/resolver.js b/app/assets/javascripts/discourse-common/addon/resolver.js
index 079161f604..45c0655643 100644
--- a/app/assets/javascripts/discourse-common/addon/resolver.js
+++ b/app/assets/javascripts/discourse-common/addon/resolver.js
@@ -1,10 +1,10 @@
-import Ember from "ember";
 import { dasherize, decamelize } from "@ember/string";
 import deprecated from "discourse-common/lib/deprecated";
 import { findHelper } from "discourse-common/lib/helpers";
 import SuffixTrie from "discourse-common/lib/suffix-trie";
 import Resolver from "ember-resolver";
 import { buildResolver as buildLegacyResolver } from "discourse-common/lib/legacy-resolver";
+import DiscourseTemplateMap from "discourse-common/lib/discourse-template-map";
 
 let _options = {};
 let moduleSuffixTrie = null;
@@ -287,21 +287,19 @@ export function buildResolver(baseName) {
 
     resolveTemplate(parsedName) {
       return (
-        this.findPluginMobileTemplate(parsedName) ||
-        this.findPluginTemplate(parsedName) ||
         this.findMobileTemplate(parsedName) ||
         this.findTemplate(parsedName) ||
         this.findAdminTemplate(parsedName) ||
         this.findWizardTemplate(parsedName) ||
         this.findLoadingTemplate(parsedName) ||
         this.findConnectorTemplate(parsedName) ||
-        Ember.TEMPLATES.not_found
+        this.discourseTemplateModule("not_found")
       );
     }
 
     findLoadingTemplate(parsedName) {
       if (parsedName.fullNameWithoutType.match(/loading$/)) {
-        return Ember.TEMPLATES.loading;
+        return this.discourseTemplateModule("loading");
       }
     }
 
@@ -312,17 +310,7 @@ export function buildResolver(baseName) {
             .replace("template:connectors/", "template:")
             .replace("components/", "")
         );
-        return this.findTemplate(connectorParsedName, "javascripts/");
-      }
-    }
-
-    findPluginTemplate(parsedName) {
-      return this.findTemplate(parsedName, "javascripts/");
-    }
-
-    findPluginMobileTemplate(parsedName) {
-      if (_options.mobileView) {
-        return this.findTemplate(parsedName, "javascripts/mobile/");
+        return this.findTemplate(connectorParsedName);
       }
     }
 
@@ -332,31 +320,43 @@ export function buildResolver(baseName) {
       }
     }
 
+    /**
+     * Given a template path, this function will return a template, taking into account
+     * priority rules for theme and plugin overrides. See `lib/discourse-template-map.js`
+     */
+    discourseTemplateModule(name) {
+      const resolvedName = DiscourseTemplateMap.resolve(name);
+      if (resolvedName) {
+        return require(resolvedName).default;
+      }
+    }
+
     findTemplate(parsedName, prefix) {
       prefix = prefix || "";
 
       const withoutType = parsedName.fullNameWithoutType,
         underscored = decamelize(withoutType).replace(/-/g, "_"),
-        segments = withoutType.split("/"),
-        templates = Ember.TEMPLATES;
+        segments = withoutType.split("/");
 
       return (
         // Convert dots and dashes to slashes
-        templates[prefix + withoutType.replace(/[\.-]/g, "/")] ||
+        this.discourseTemplateModule(
+          prefix + withoutType.replace(/[\.-]/g, "/")
+        ) ||
         // Default unmodified behavior of original resolveTemplate.
-        templates[prefix + withoutType] ||
+        this.discourseTemplateModule(prefix + withoutType) ||
         // Underscored without namespace
-        templates[prefix + underscored] ||
+        this.discourseTemplateModule(prefix + underscored) ||
         // Underscored with first segment as directory
-        templates[prefix + underscored.replace("_", "/")] ||
+        this.discourseTemplateModule(prefix + underscored.replace("_", "/")) ||
         // Underscore only the last segment
-        templates[
+        this.discourseTemplateModule(
           `${prefix}${segments.slice(0, -1).join("/")}/${segments[
             segments.length - 1
           ].replace(/-/g, "_")}`
-        ] ||
+        ) ||
         // All dasherized
-        templates[prefix + withoutType.replace(/\//g, "-")]
+        this.discourseTemplateModule(prefix + withoutType.replace(/\//g, "-"))
       );
     }
 
@@ -364,17 +364,15 @@ export function buildResolver(baseName) {
     // (similar to how discourse lays out templates)
     findAdminTemplate(parsedName) {
       if (parsedName.fullNameWithoutType === "admin") {
-        return Ember.TEMPLATES["admin/templates/admin"];
+        return this.discourseTemplateModule("admin/templates/admin");
       }
 
       let namespaced, match;
 
       if (parsedName.fullNameWithoutType.startsWith("components/")) {
         return (
-          // Built-in
           this.findTemplate(parsedName, "admin/templates/") ||
-          // Plugin
-          this.findTemplate(parsedName, "javascripts/admin/")
+          this.findTemplate(parsedName, "admin/") // Nested under discourse/templates/admin (e.g. from plugins)
         );
       } else if (/^admin[_\.-]/.test(parsedName.fullNameWithoutType)) {
         namespaced = parsedName.fullNameWithoutType.slice(6);
@@ -389,11 +387,9 @@ export function buildResolver(baseName) {
       if (namespaced) {
         let adminParsedName = this.parseName(`template:${namespaced}`);
         resolved =
-          // Built-in
           this.findTemplate(adminParsedName, "admin/templates/") ||
           this.findTemplate(parsedName, "admin/templates/") ||
-          // Plugin
-          this.findTemplate(adminParsedName, "javascripts/admin/");
+          this.findTemplate(adminParsedName, "admin/"); // Nested under discourse/templates/admin (e.g. from plugin)
       }
 
       return resolved;
@@ -401,7 +397,7 @@ export function buildResolver(baseName) {
 
     findWizardTemplate(parsedName) {
       if (parsedName.fullNameWithoutType === "wizard") {
-        return Ember.TEMPLATES["wizard/templates/wizard"];
+        return this.discourseTemplateModule("wizard/templates/wizard");
       }
 
       let namespaced;
@@ -415,10 +411,10 @@ export function buildResolver(baseName) {
       }
 
       if (namespaced) {
-        let adminParsedName = this.parseName(
+        let wizardParsedName = this.parseName(
           `template:wizard/templates/${namespaced}`
         );
-        return this.findTemplate(adminParsedName);
+        return this.findTemplate(wizardParsedName);
       }
     }
   };
diff --git a/app/assets/javascripts/discourse/app/components/reviewable-item.js b/app/assets/javascripts/discourse/app/components/reviewable-item.js
index fed71c9789..10cae579f6 100644
--- a/app/assets/javascripts/discourse/app/components/reviewable-item.js
+++ b/app/assets/javascripts/discourse/app/components/reviewable-item.js
@@ -9,7 +9,7 @@ import { popupAjaxError } from "discourse/lib/ajax-error";
 import { action, set } from "@ember/object";
 import showModal from "discourse/lib/show-modal";
 import { inject as service } from "@ember/service";
-import Ember from "ember";
+import { getOwner } from "discourse-common/lib/get-owner";
 
 let _components = {};
 
@@ -106,12 +106,11 @@ export default Component.extend({
       return _components[type];
     }
 
-    let dasherized = dasherize(type);
-    let templatePath = `components/${dasherized}`;
-    let template =
-      Ember.TEMPLATES[`${templatePath}`] ||
-      Ember.TEMPLATES[`javascripts/${templatePath}`];
-    _components[type] = template ? dasherized : null;
+    const dasherized = dasherize(type);
+    const componentExists = getOwner(this).hasRegistration(
+      `component:${dasherized}`
+    );
+    _components[type] = componentExists ? dasherized : null;
     return _components[type];
   },
 
diff --git a/app/assets/javascripts/discourse/app/initializers/eager-load-raw-templates.js b/app/assets/javascripts/discourse/app/initializers/eager-load-raw-templates.js
new file mode 100644
index 0000000000..47be0b1303
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/initializers/eager-load-raw-templates.js
@@ -0,0 +1,9 @@
+import { eagerLoadRawTemplateModules } from "discourse-common/lib/raw-templates";
+
+export default {
+  name: "eager-load-raw-templates",
+
+  initialize() {
+    eagerLoadRawTemplateModules();
+  },
+};
diff --git a/app/assets/javascripts/discourse/app/initializers/populate-template-map.js b/app/assets/javascripts/discourse/app/initializers/populate-template-map.js
new file mode 100644
index 0000000000..4d198fed51
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/initializers/populate-template-map.js
@@ -0,0 +1,8 @@
+import discourseTemplateMap from "discourse-common/lib/discourse-template-map";
+
+export default {
+  name: "populate-template-map",
+  initialize() {
+    discourseTemplateMap.setModuleNames(Object.keys(requirejs.entries));
+  },
+};
diff --git a/app/assets/javascripts/discourse/app/lib/plugin-connectors.js b/app/assets/javascripts/discourse/app/lib/plugin-connectors.js
index a276c1fe1b..0a9e07146c 100644
--- a/app/assets/javascripts/discourse/app/lib/plugin-connectors.js
+++ b/app/assets/javascripts/discourse/app/lib/plugin-connectors.js
@@ -1,6 +1,6 @@
 import { buildRawConnectorCache } from "discourse-common/lib/raw-templates";
 import deprecated from "discourse-common/lib/deprecated";
-import Ember from "ember";
+import DiscourseTemplateMap from "discourse-common/lib/discourse-template-map";
 
 let _connectorCache;
 let _rawConnectorCache;
@@ -25,11 +25,11 @@ const DefaultConnectorClass = {
   teardownComponent() {},
 };
 
-function findOutlets(collection, callback) {
-  Object.keys(collection).forEach(function (res) {
-    if (res.includes("/connectors/")) {
-      const segments = res.split("/");
-      let outletName = segments[segments.length - 2];
+function findOutlets(keys, callback) {
+  keys.forEach(function (res) {
+    const segments = res.split("/");
+    if (segments.includes("connectors")) {
+      const outletName = segments[segments.length - 2];
       const uniqueName = segments[segments.length - 1];
 
       callback(outletName, res, uniqueName);
@@ -45,7 +45,7 @@ export function clearCache() {
 function findClass(outletName, uniqueName) {
   if (!_classPaths) {
     _classPaths = {};
-    findOutlets(require._eak_seen, (outlet, res, un) => {
+    findOutlets(Object.keys(require._eak_seen), (outlet, res, un) => {
       const possibleConnectorClass = requirejs(res).default;
       if (possibleConnectorClass.__id) {
         // This is the template, not the connector class
@@ -63,20 +63,31 @@ function findClass(outletName, uniqueName) {
     : DefaultConnectorClass;
 }
 
+/**
+ * Clear the cache of connectors. Should only be used in tests when
+ * `requirejs.entries` is changed.
+ */
+export function expireConnectorCache() {
+  _connectorCache = null;
+}
+
 function buildConnectorCache() {
   _connectorCache = {};
 
-  findOutlets(Ember.TEMPLATES, (outletName, resource, uniqueName) => {
-    _connectorCache[outletName] = _connectorCache[outletName] || [];
+  findOutlets(
+    DiscourseTemplateMap.keys(),
+    (outletName, resource, uniqueName) => {
+      _connectorCache[outletName] = _connectorCache[outletName] || [];
 
-    _connectorCache[outletName].push({
-      outletName,
-      templateName: resource.replace("javascripts/", ""),
-      template: Ember.TEMPLATES[resource],
-      classNames: `${outletName}-outlet ${uniqueName}`,
-      connectorClass: findClass(outletName, uniqueName),
-    });
-  });
+      _connectorCache[outletName].push({
+        outletName,
+        templateName: resource,
+        template: require(DiscourseTemplateMap.resolve(resource)).default,
+        classNames: `${outletName}-outlet ${uniqueName}`,
+        connectorClass: findClass(outletName, uniqueName),
+      });
+    }
+  );
 }
 
 export function connectorsFor(outletName) {
diff --git a/app/assets/javascripts/discourse/public/assets/scripts/discourse-boot.js b/app/assets/javascripts/discourse/public/assets/scripts/discourse-boot.js
index d9d96d27b9..964fb0b5bf 100644
--- a/app/assets/javascripts/discourse/public/assets/scripts/discourse-boot.js
+++ b/app/assets/javascripts/discourse/public/assets/scripts/discourse-boot.js
@@ -3,50 +3,6 @@
     throw "Unsupported browser detected";
   }
 
-  // TODO: Remove this and have resolver find the templates
-  const discoursePrefix = "discourse/templates/";
-  const adminPrefix = "admin/templates/";
-  const wizardPrefix = "wizard/templates/";
-  const discoursePrefixLength = discoursePrefix.length;
-
-  const pluginRegex = /^discourse\/plugins\/([^\/]+)\//;
-  const themeRegex = /^discourse\/theme-([^\/]+)\//;
-
-  Object.keys(requirejs.entries).forEach(function (key) {
-    let templateKey;
-    let pluginName;
-    let themeId;
-    if (key.startsWith(discoursePrefix)) {
-      templateKey = key.slice(discoursePrefixLength);
-    } else if (key.startsWith(adminPrefix) || key.startsWith(wizardPrefix)) {
-      templateKey = key;
-    } else if (
-      (pluginName = key.match(pluginRegex)?.[1]) &&
-      key.includes("/templates/") &&
-      require(key).default.__id // really is a template
-    ) {
-      // This logic mimics the old sprockets compilation system which used to
-      // output templates directly to `Ember.TEMPLATES` with this naming logic
-      templateKey = key.slice(`discourse/plugins/${pluginName}/`.length);
-      templateKey = templateKey.replace("discourse/templates/", "");
-      templateKey = `javascripts/${templateKey}`;
-    } else if (
-      (themeId = key.match(themeRegex)?.[1]) &&
-      key.includes("/templates/")
-    ) {
-      // And likewise for themes - this mimics the old logic
-      templateKey = key.slice(`discourse/theme-${themeId}/`.length);
-      templateKey = templateKey.replace("discourse/templates/", "");
-      if (!templateKey.startsWith("javascripts/")) {
-        templateKey = `javascripts/${templateKey}`;
-      }
-    }
-
-    if (templateKey) {
-      Ember.TEMPLATES[templateKey] = require(key).default;
-    }
-  });
-
   window.__widget_helpers = require("discourse-widget-hbs/helpers").default;
 
   // TODO: Eliminate this global
diff --git a/app/assets/javascripts/discourse/tests/acceptance/custom-html-template-test.js b/app/assets/javascripts/discourse/tests/acceptance/custom-html-template-test.js
index 117084efd7..c6825446a0 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/custom-html-template-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/custom-html-template-test.js
@@ -2,15 +2,14 @@ import { acceptance, query } from "discourse/tests/helpers/qunit-helpers";
 import { hbs } from "ember-cli-htmlbars";
 import { test } from "qunit";
 import { visit } from "@ember/test-helpers";
-import Ember from "ember";
+import { registerTemplateModule } from "discourse/tests/helpers/template-module-helper";
 
 acceptance("CustomHTML template", function (needs) {
   needs.hooks.beforeEach(() => {
-    Ember.TEMPLATES["top"] = hbs`<span class='top-span'>TOP</span>`;
-  });
-
-  needs.hooks.afterEach(() => {
-    delete Ember.TEMPLATES["top"];
+    registerTemplateModule(
+      "discourse/templates/top",
+      hbs`<span class='top-span'>TOP</span>`
+    );
   });
 
   test("renders custom template", async function (assert) {
diff --git a/app/assets/javascripts/discourse/tests/acceptance/modal-test.js b/app/assets/javascripts/discourse/tests/acceptance/modal-test.js
index f2257ab9f3..398c18eda4 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/modal-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/modal-test.js
@@ -10,7 +10,7 @@ import { test } from "qunit";
 import I18n from "I18n";
 import { hbs } from "ember-cli-htmlbars";
 import showModal from "discourse/lib/show-modal";
-import Ember from "ember";
+import { registerTemplateModule } from "../helpers/template-module-helper";
 
 acceptance("Modal", function (needs) {
   let _translations;
@@ -54,9 +54,10 @@ acceptance("Modal", function (needs) {
     await triggerKeyEvent("#main-outlet", "keydown", "Escape");
     assert.ok(!exists(".d-modal:visible"), "ESC should close the modal");
 
-    Ember.TEMPLATES[
-      "modal/not-dismissable"
-    ] = hbs`{{#d-modal-body title="" class="" dismissable=false}}test{{/d-modal-body}}`;
+    registerTemplateModule(
+      "discourse/templates/modal/not-dismissable",
+      hbs`{{#d-modal-body title="" class="" dismissable=false}}test{{/d-modal-body}}`
+    );
 
     showModal("not-dismissable", {});
     await settled();
@@ -78,7 +79,10 @@ acceptance("Modal", function (needs) {
   });
 
   test("rawTitle in modal panels", async function (assert) {
-    Ember.TEMPLATES["modal/test-raw-title-panels"] = hbs``;
+    registerTemplateModule(
+      "discourse/templates/modal/test-raw-title-panels",
+      hbs``
+    );
     const panels = [
       { id: "test1", rawTitle: "Test 1" },
       { id: "test2", rawTitle: "Test 2" },
@@ -96,10 +100,11 @@ acceptance("Modal", function (needs) {
   });
 
   test("modal title", async function (assert) {
-    Ember.TEMPLATES["modal/test-title"] = hbs``;
-    Ember.TEMPLATES[
-      "modal/test-title-with-body"
-    ] = hbs`{{#d-modal-body}}test{{/d-modal-body}}`;
+    registerTemplateModule("discourse/templates/modal/test-title", hbs``);
+    registerTemplateModule(
+      "discourse/templates/modal/test-title-with-body",
+      hbs`{{#d-modal-body}}test{{/d-modal-body}}`
+    );
 
     await visit("/");
 
diff --git a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-connector-class-test.js b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-connector-class-test.js
index 712a07fa13..89fb051f26 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-connector-class-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-connector-class-test.js
@@ -9,9 +9,9 @@ import { action } from "@ember/object";
 import { extraConnectorClass } from "discourse/lib/plugin-connectors";
 import { hbs } from "ember-cli-htmlbars";
 import { test } from "qunit";
-import Ember from "ember";
+import { registerTemplateModule } from "discourse/tests/helpers/template-module-helper";
 
-const PREFIX = "javascripts/single-test/connectors";
+const PREFIX = "discourse/plugins/some-plugin/templates/connectors";
 
 acceptance("Plugin Outlet - Connector Class", function (needs) {
   needs.hooks.beforeEach(() => {
@@ -49,25 +49,22 @@ acceptance("Plugin Outlet - Connector Class", function (needs) {
       },
     });
 
-    Ember.TEMPLATES[
-      `${PREFIX}/user-profile-primary/hello`
-    ] = hbs`<span class='hello-username'>{{model.username}}</span>
+    registerTemplateModule(
+      `${PREFIX}/user-profile-primary/hello`,
+      hbs`<span class='hello-username'>{{model.username}}</span>
         <button class='say-hello' {{on "click" (action "sayHello")}}></button>
         <button class='say-hello-using-this' {{on "click" this.sayHello}}></button>
-        <span class='hello-result'>{{hello}}</span>`;
-    Ember.TEMPLATES[
-      `${PREFIX}/user-profile-primary/hi`
-    ] = hbs`<button class='say-hi' {{on "click" (action "sayHi")}}></button>
-        <span class='hi-result'>{{hi}}</span>`;
-    Ember.TEMPLATES[
-      `${PREFIX}/user-profile-primary/dont-render`
-    ] = hbs`I'm not rendered!`;
-  });
-
-  needs.hooks.afterEach(() => {
-    delete Ember.TEMPLATES[`${PREFIX}/user-profile-primary/hello`];
-    delete Ember.TEMPLATES[`${PREFIX}/user-profile-primary/hi`];
-    delete Ember.TEMPLATES[`${PREFIX}/user-profile-primary/dont-render`];
+        <span class='hello-result'>{{hello}}</span>`
+    );
+    registerTemplateModule(
+      `${PREFIX}/user-profile-primary/hi`,
+      hbs`<button class='say-hi' {{on "click" (action "sayHi")}}></button>
+        <span class='hi-result'>{{hi}}</span>`
+    );
+    registerTemplateModule(
+      `${PREFIX}/user-profile-primary/dont-render`,
+      hbs`I'm not rendered!`
+    );
   });
 
   test("Renders a template into the outlet", async function (assert) {
diff --git a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-decorator-test.js b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-decorator-test.js
index c287449f09..e269882d8d 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-decorator-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-decorator-test.js
@@ -7,16 +7,22 @@ import { hbs } from "ember-cli-htmlbars";
 import { test } from "qunit";
 import { visit } from "@ember/test-helpers";
 import { withPluginApi } from "discourse/lib/plugin-api";
-import Ember from "ember";
+import { registerTemplateModule } from "../helpers/template-module-helper";
 
-const PREFIX = "javascripts/single-test/connectors";
+const PREFIX = "discourse/plugins/some-plugin/templates/connectors";
 
 acceptance("Plugin Outlet - Decorator", function (needs) {
   needs.user();
 
   needs.hooks.beforeEach(() => {
-    Ember.TEMPLATES[`${PREFIX}/discovery-list-container-top/foo`] = hbs`FOO`;
-    Ember.TEMPLATES[`${PREFIX}/discovery-list-container-top/bar`] = hbs`BAR`;
+    registerTemplateModule(
+      `${PREFIX}/discovery-list-container-top/foo`,
+      hbs`FOO`
+    );
+    registerTemplateModule(
+      `${PREFIX}/discovery-list-container-top/bar`,
+      hbs`BAR`
+    );
 
     withPluginApi("0.8.38", (api) => {
       api.decoratePluginOutlet(
@@ -37,11 +43,6 @@ acceptance("Plugin Outlet - Decorator", function (needs) {
     });
   });
 
-  needs.hooks.afterEach(() => {
-    delete Ember.TEMPLATES[`${PREFIX}/discovery-list-container-top/foo`];
-    delete Ember.TEMPLATES[`${PREFIX}/discovery-list-container-top/bar`];
-  });
-
   test("Calls the plugin callback with the rendered outlet", async function (assert) {
     await visit("/");
 
diff --git a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-multi-template-test.js b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-multi-template-test.js
index b5e70c3a5a..ba81c83a1f 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-multi-template-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-multi-template-test.js
@@ -6,21 +6,17 @@ import {
 import { hbs } from "ember-cli-htmlbars";
 import { test } from "qunit";
 import { visit } from "@ember/test-helpers";
-import Ember from "ember";
+import { registerTemplateModule } from "../helpers/template-module-helper";
 
-const HELLO = "javascripts/multi-test/connectors/user-profile-primary/hello";
+const HELLO =
+  "discourse/plugins/my-plugin/templates/connectors/user-profile-primary/hello";
 const GOODBYE =
-  "javascripts/multi-test/connectors/user-profile-primary/goodbye";
+  "discourse/plugins/my-plugin/templates/connectors/user-profile-primary/goodbye";
 
 acceptance("Plugin Outlet - Multi Template", function (needs) {
   needs.hooks.beforeEach(() => {
-    Ember.TEMPLATES[HELLO] = hbs`<span class='hello-span'>Hello</span>`;
-    Ember.TEMPLATES[GOODBYE] = hbs`<span class='bye-span'>Goodbye</span>`;
-  });
-
-  needs.hooks.afterEach(() => {
-    delete Ember.TEMPLATES[HELLO];
-    delete Ember.TEMPLATES[GOODBYE];
+    registerTemplateModule(HELLO, hbs`<span class='hello-span'>Hello</span>`);
+    registerTemplateModule(GOODBYE, hbs`<span class='bye-span'>Goodbye</span>`);
   });
 
   test("Renders a template into the outlet", async function (assert) {
diff --git a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-single-template-test.js b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-single-template-test.js
index 1f9e06d096..e1a0cc62c0 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-single-template-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/plugin-outlet-single-template-test.js
@@ -6,20 +6,17 @@ import {
 import { hbs } from "ember-cli-htmlbars";
 import { test } from "qunit";
 import { visit } from "@ember/test-helpers";
-import Ember from "ember";
+import { registerTemplateModule } from "../helpers/template-module-helper";
 
-const CONNECTOR =
-  "javascripts/single-test/connectors/user-profile-primary/hello";
+const CONNECTOR_MODULE =
+  "discourse/theme-12/templates/connectors/user-profile-primary/hello";
 
 acceptance("Plugin Outlet - Single Template", function (needs) {
   needs.hooks.beforeEach(() => {
-    Ember.TEMPLATES[
-      CONNECTOR
-    ] = hbs`<span class='hello-username'>{{model.username}}</span>`;
-  });
-
-  needs.hooks.afterEach(() => {
-    delete Ember.TEMPLATES[CONNECTOR];
+    registerTemplateModule(
+      CONNECTOR_MODULE,
+      hbs`<span class='hello-username'>{{model.username}}</span>`
+    );
   });
 
   test("Renders a template into the outlet", async function (assert) {
diff --git a/app/assets/javascripts/discourse/tests/helpers/qunit-helpers.js b/app/assets/javascripts/discourse/tests/helpers/qunit-helpers.js
index 5c2c3a609b..da71ce3683 100644
--- a/app/assets/javascripts/discourse/tests/helpers/qunit-helpers.js
+++ b/app/assets/javascripts/discourse/tests/helpers/qunit-helpers.js
@@ -76,6 +76,7 @@ import { resetNotificationTypeRenderers } from "discourse/lib/notification-types
 import { resetUserMenuTabs } from "discourse/lib/user-menu/tab";
 import { reset as resetLinkLookup } from "discourse/lib/link-lookup";
 import { resetModelTransformers } from "discourse/lib/model-transformers";
+import { cleanupTemporaryTemplateRegistrations } from "./template-module-helper";
 
 export function currentUser() {
   return User.create(sessionFixtures["/session/current.json"].current_user);
@@ -207,6 +208,7 @@ export function testCleanup(container, app) {
   resetUserMenuTabs();
   resetLinkLookup();
   resetModelTransformers();
+  cleanupTemporaryTemplateRegistrations();
 }
 
 export function discourseModule(name, options) {
diff --git a/app/assets/javascripts/discourse/tests/helpers/template-module-helper.js b/app/assets/javascripts/discourse/tests/helpers/template-module-helper.js
new file mode 100644
index 0000000000..ae1930d805
--- /dev/null
+++ b/app/assets/javascripts/discourse/tests/helpers/template-module-helper.js
@@ -0,0 +1,40 @@
+import DiscourseTemplateMap from "discourse-common/lib/discourse-template-map";
+import { expireConnectorCache } from "discourse/lib/plugin-connectors";
+
+const modifications = [];
+
+function generateTemplateModule(template) {
+  return function (_exports) {
+    Object.defineProperty(_exports, "__esModule", {
+      value: true,
+    });
+    _exports.default = template;
+  };
+}
+
+export function registerTemplateModule(moduleName, template) {
+  const modificationData = {
+    moduleName,
+    existingModule: requirejs.entries[moduleName],
+  };
+  delete requirejs.entries[moduleName];
+  define(moduleName, ["exports"], generateTemplateModule(template));
+  modifications.push(modificationData);
+  expireConnectorCache();
+  DiscourseTemplateMap.setModuleNames(Object.keys(requirejs.entries));
+}
+
+export function cleanupTemporaryTemplateRegistrations() {
+  for (const modificationData of modifications.reverse()) {
+    const { moduleName, existingModule } = modificationData;
+    delete requirejs.entries[moduleName];
+    if (existingModule) {
+      requirejs.entries[moduleName] = existingModule;
+    }
+  }
+  if (modifications.length) {
+    expireConnectorCache();
+    DiscourseTemplateMap.setModuleNames(Object.keys(requirejs.entries));
+  }
+  modifications.clear();
+}
diff --git a/app/assets/javascripts/discourse/tests/unit/ember/resolver-test.js b/app/assets/javascripts/discourse/tests/unit/ember/resolver-test.js
index 14aafdb325..04e48df1a1 100644
--- a/app/assets/javascripts/discourse/tests/unit/ember/resolver-test.js
+++ b/app/assets/javascripts/discourse/tests/unit/ember/resolver-test.js
@@ -1,8 +1,8 @@
 import { buildResolver, setResolverOption } from "discourse-common/resolver";
 import { module, test } from "qunit";
-import Ember from "ember";
+import { registerTemplateModule } from "discourse/tests/helpers/template-module-helper";
+import DiscourseTemplateMap from "discourse-common/lib/discourse-template-map";
 
-let originalTemplates;
 let resolver;
 
 function lookupTemplate(assert, name, expectedTemplate, message) {
@@ -11,57 +11,71 @@ function lookupTemplate(assert, name, expectedTemplate, message) {
   assert.strictEqual(result, expectedTemplate, message);
 }
 
-function setTemplates(lookupTemplateStrings) {
-  lookupTemplateStrings.forEach(function (lookupTemplateString) {
-    Ember.TEMPLATES[lookupTemplateString] = lookupTemplateString;
-  });
+function setTemplates(templateModuleNames) {
+  for (const name of templateModuleNames) {
+    registerTemplateModule(name, name);
+  }
 }
 
 const DiscourseResolver = buildResolver("discourse");
 
 module("Unit | Ember | resolver", function (hooks) {
   hooks.beforeEach(function () {
-    originalTemplates = Ember.TEMPLATES;
-    Ember.TEMPLATES = {};
-
+    DiscourseTemplateMap.setModuleNames(Object.keys(requirejs.entries));
     resolver = DiscourseResolver.create({
       namespace: { modulePrefix: "discourse" },
     });
   });
 
-  hooks.afterEach(function () {
-    Ember.TEMPLATES = originalTemplates;
-  });
-
   test("finds templates in top level dir", function (assert) {
-    setTemplates(["foobar", "fooBar", "foo_bar", "foo.bar"]);
+    setTemplates([
+      "discourse/templates/foobar",
+      "discourse/templates/fooBar",
+      "discourse/templates/foo_bar",
+      "discourse/templates/foo.bar",
+    ]);
 
     // Default unmodified behavior
-    lookupTemplate(assert, "template:foobar", "foobar", "by lowcased name");
+    lookupTemplate(
+      assert,
+      "template:foobar",
+      "discourse/templates/foobar",
+      "by lowcased name"
+    );
 
     // Default unmodified behavior
-    lookupTemplate(assert, "template:fooBar", "fooBar", "by camel cased name");
+    lookupTemplate(
+      assert,
+      "template:fooBar",
+      "discourse/templates/fooBar",
+      "by camel cased name"
+    );
 
     // Default unmodified behavior
     lookupTemplate(
       assert,
       "template:foo_bar",
-      "foo_bar",
+      "discourse/templates/foo_bar",
       "by underscored name"
     );
 
     // Default unmodified behavior
-    lookupTemplate(assert, "template:foo.bar", "foo.bar", "by dotted name");
+    lookupTemplate(
+      assert,
+      "template:foo.bar",
+      "discourse/templates/foo.bar",
+      "by dotted name"
+    );
   });
 
   test("finds templates in first-level subdir", function (assert) {
-    setTemplates(["foo/bar_baz"]);
+    setTemplates(["discourse/templates/foo/bar_baz"]);
 
     // Default unmodified behavior
     lookupTemplate(
       assert,
       "template:foo/bar_baz",
-      "foo/bar_baz",
+      "discourse/templates/foo/bar_baz",
       "with subdir defined by slash"
     );
 
@@ -69,7 +83,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo.bar_baz",
-      "foo/bar_baz",
+      "discourse/templates/foo/bar_baz",
       "with subdir defined by dot"
     );
 
@@ -77,7 +91,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo-bar_baz",
-      "foo/bar_baz",
+      "discourse/templates/foo/bar_baz",
       "with subdir defined by dash"
     );
 
@@ -85,7 +99,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:fooBarBaz",
-      "foo/bar_baz",
+      "discourse/templates/foo/bar_baz",
       "with subdir defined by first camel case and the rest of camel cases converted to underscores"
     );
 
@@ -93,19 +107,25 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo_bar_baz",
-      "foo/bar_baz",
+      "discourse/templates/foo/bar_baz",
       "with subdir defined by first underscore"
     );
   });
 
   test("resolves precedence between overlapping top level dir and first level subdir templates", function (assert) {
-    setTemplates(["fooBar", "foo_bar", "foo.bar", "foo/bar", "baz/qux"]);
+    setTemplates([
+      "discourse/templates/fooBar",
+      "discourse/templates/foo_bar",
+      "discourse/templates/foo.bar",
+      "discourse/templates/foo/bar",
+      "discourse/templates/baz/qux",
+    ]);
 
     // Directories are prioritized when dotted
     lookupTemplate(
       assert,
       "template:foo.bar",
-      "foo/bar",
+      "discourse/templates/foo/bar",
       "preferring first level subdir for dotted name"
     );
 
@@ -113,7 +133,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo-bar",
-      "foo/bar",
+      "discourse/templates/foo/bar",
       "preferring first level subdir for dotted name"
     );
 
@@ -121,7 +141,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:fooBar",
-      "fooBar",
+      "discourse/templates/fooBar",
       "preferring top level dir for camel cased name"
     );
 
@@ -129,7 +149,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo_bar",
-      "foo_bar",
+      "discourse/templates/foo_bar",
       "preferring top level dir for underscored name"
     );
 
@@ -137,19 +157,19 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:baz-qux",
-      "baz/qux",
+      "discourse/templates/baz/qux",
       "fallback subdir for dashed name"
     );
   });
 
   test("finds templates in subdir deeper than one level", function (assert) {
-    setTemplates(["foo/bar/baz/qux"]);
+    setTemplates(["discourse/templates/foo/bar/baz/qux"]);
 
     // Default unmodified
     lookupTemplate(
       assert,
       "template:foo/bar/baz/qux",
-      "foo/bar/baz/qux",
+      "discourse/templates/foo/bar/baz/qux",
       "for subdirs defined by slashes"
     );
 
@@ -157,7 +177,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo.bar.baz.qux",
-      "foo/bar/baz/qux",
+      "discourse/templates/foo/bar/baz/qux",
       "for subdirs defined by dots"
     );
 
@@ -165,7 +185,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo/bar/bazQux",
-      "foo/bar/baz/qux",
+      "discourse/templates/foo/bar/baz/qux",
       "for subdirs defined by slashes plus one camel case"
     );
 
@@ -173,7 +193,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo/bar/baz_qux",
-      "foo/bar/baz/qux",
+      "discourse/templates/foo/bar/baz/qux",
       "for subdirs defined by slashes plus one underscore"
     );
 
@@ -211,7 +231,12 @@ module("Unit | Ember | resolver", function (hooks) {
   });
 
   test("resolves mobile templates to 'mobile/' namespace", function (assert) {
-    setTemplates(["mobile/foo", "bar", "mobile/bar", "baz"]);
+    setTemplates([
+      "discourse/templates/mobile/foo",
+      "discourse/templates/bar",
+      "discourse/templates/mobile/bar",
+      "discourse/templates/baz",
+    ]);
 
     setResolverOption("mobileView", true);
 
@@ -219,7 +244,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:foo",
-      "mobile/foo",
+      "discourse/templates/mobile/foo",
       "finding mobile version even if normal one is not present"
     );
 
@@ -227,7 +252,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:bar",
-      "mobile/bar",
+      "discourse/templates/mobile/bar",
       "preferring mobile version when both mobile and normal versions are present"
     );
 
@@ -235,71 +260,87 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:baz",
-      "baz",
+      "discourse/templates/baz",
       "falling back to a normal version when mobile version is not present"
     );
   });
 
-  test("resolves plugin templates to 'javascripts/' namespace", function (assert) {
-    setTemplates(["javascripts/foo", "bar", "javascripts/bar", "baz"]);
+  test("resolves templates to plugin and theme namespaces", function (assert) {
+    setTemplates([
+      "discourse/plugins/my-plugin/discourse/templates/foo",
+      "discourse/templates/bar",
+      "discourse/plugins/my-plugin/discourse/templates/bar",
+      "discourse/templates/baz",
+      "discourse/plugins/my-plugin/discourse/templates/baz",
+      "discourse/theme-12/discourse/templates/baz",
+      "discourse/templates/qux",
+    ]);
 
-    // Default with javascripts/ added
+    // Defined in plugin only
     lookupTemplate(
       assert,
       "template:foo",
-      "javascripts/foo",
+      "discourse/plugins/my-plugin/discourse/templates/foo",
       "finding plugin version even if normal one is not present"
     );
 
-    // Default with javascripts/ added, takes precedence
+    // Defined in core and plugin
     lookupTemplate(
       assert,
       "template:bar",
-      "javascripts/bar",
-      "preferring plugin version when both versions are present"
+      "discourse/plugins/my-plugin/discourse/templates/bar",
+      "prefers plugin version over core"
     );
 
-    // Default when javascripts version not present
+    // Defined in core and plugin and theme
     lookupTemplate(
       assert,
       "template:baz",
-      "baz",
-      "falling back to a normal version when plugin version is not present"
+      "discourse/theme-12/discourse/templates/baz",
+      "prefers theme version over plugin and core"
+    );
+
+    // Defined in core only
+    lookupTemplate(
+      assert,
+      "template:qux",
+      "discourse/templates/qux",
+      "uses core if there are no theme/plugin definitions"
     );
   });
 
-  test("resolves plugin mobile templates to 'javascripts/mobile/' namespace", function (assert) {
+  test("resolves plugin mobile templates", function (assert) {
     setTemplates([
-      "javascripts/mobile/foo",
-      "javascripts/mobile/bar",
-      "javascripts/bar",
-      "javascripts/mobile/baz",
-      "mobile/baz",
+      "discourse/plugins/my-plugin/discourse/templates/mobile/foo",
+      "discourse/plugins/my-plugin/discourse/templates/mobile/bar",
+      "discourse/plugins/my-plugin/discourse/templates/bar",
+      "discourse/plugins/my-plugin/discourse/templates/mobile/baz",
+      "discourse/templates/mobile/baz",
     ]);
 
     setResolverOption("mobileView", true);
 
-    // Default with javascripts/mobile/ added
+    // Default with plugin template override
     lookupTemplate(
       assert,
       "template:foo",
-      "javascripts/mobile/foo",
+      "discourse/plugins/my-plugin/discourse/templates/mobile/foo",
       "finding plugin version even if normal one is not present"
     );
 
-    // Default with javascripts/mobile added, takes precedence over non-mobile
+    // Default with plugin mobile added, takes precedence over non-mobile
     lookupTemplate(
       assert,
       "template:bar",
-      "javascripts/mobile/bar",
+      "discourse/plugins/my-plugin/discourse/templates/mobile/bar",
       "preferring plugin mobile version when both non-mobile plugin version is also present"
     );
 
-    // Default with javascripts/mobile when non-plugin mobile version is present
+    // Default with when non-plugin mobile version is present
     lookupTemplate(
       assert,
       "template:baz",
-      "javascripts/mobile/baz",
+      "discourse/plugins/my-plugin/discourse/templates/mobile/baz",
       "preferring plugin mobile version over non-plugin mobile version"
     );
   });
@@ -307,13 +348,13 @@ module("Unit | Ember | resolver", function (hooks) {
   test("resolves templates with 'admin' prefix", function (assert) {
     setTemplates([
       "admin/templates/foo",
-      "adminBar",
-      "admin_bar",
-      "admin.bar",
+      "discourse/templates/adminBar",
+      "discourse/templates/admin_bar",
+      "discourse/templates/admin.bar",
       "admin/templates/bar",
       "admin/templates/dashboard_general",
-      "admin-baz-qux",
-      "javascripts/admin/plugin-template",
+      "discourse/templates/admin-baz-qux",
+      "discourse/plugins/my-plugin/discourse/templates/admin/plugin-template",
       "admin/templates/components/my-admin-component",
     ]);
 
@@ -353,7 +394,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:adminBar",
-      "adminBar",
+      "discourse/templates/adminBar",
       "but not when template with the exact camel cased name exists"
     );
 
@@ -361,7 +402,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:admin_bar",
-      "admin_bar",
+      "discourse/templates/admin_bar",
       "but not when template with the exact underscored name exists"
     );
 
@@ -369,7 +410,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:admin.bar",
-      "admin.bar",
+      "discourse/templates/admin.bar",
       "but not when template with the exact dotted name exists"
     );
 
@@ -383,14 +424,14 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:admin-baz/qux",
-      "admin-baz-qux",
+      "discourse/templates/admin-baz-qux",
       "also tries dasherized"
     );
 
     lookupTemplate(
       assert,
       "template:admin-plugin/template",
-      "javascripts/admin/plugin-template",
+      "discourse/plugins/my-plugin/discourse/templates/admin/plugin-template",
       "looks up templates in plugins"
     );
 
@@ -412,7 +453,7 @@ module("Unit | Ember | resolver", function (hooks) {
   test("resolves component templates with 'admin' prefix to 'admin/templates/' namespace", function (assert) {
     setTemplates([
       "admin/templates/components/foo",
-      "components/bar",
+      "discourse/templates/components/bar",
       "admin/templates/components/bar",
     ]);
 
@@ -428,7 +469,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:components/bar",
-      "components/bar",
+      "discourse/templates/components/bar",
       "uses standard match when both exist"
     );
   });
@@ -437,54 +478,59 @@ module("Unit | Ember | resolver", function (hooks) {
   // close to Ember's default behavior.
   // See https://guides.emberjs.com/release/routing/loading-and-error-substates/
   test("resolves loading templates", function (assert) {
-    setTemplates(["fooloading", "foo/loading", "foo_loading", "loading"]);
+    setTemplates([
+      "discourse/templates/fooloading",
+      "discourse/templates/foo/loading",
+      "discourse/templates/foo_loading",
+      "discourse/templates/loading",
+    ]);
 
     lookupTemplate(
       assert,
       "template:fooloading",
-      "fooloading",
+      "discourse/templates/fooloading",
       "exact match without separator"
     );
 
     lookupTemplate(
       assert,
       "template:foo/loading",
-      "foo/loading",
+      "discourse/templates/foo/loading",
       "exact match with slash"
     );
 
     lookupTemplate(
       assert,
       "template:foo_loading",
-      "foo_loading",
+      "discourse/templates/foo_loading",
       "exact match underscore"
     );
 
     lookupTemplate(
       assert,
       "template:barloading",
-      "loading",
+      "discourse/templates/loading",
       "fallback without separator"
     );
 
     lookupTemplate(
       assert,
       "template:bar/loading",
-      "loading",
+      "discourse/templates/loading",
       "fallback with slash"
     );
 
     lookupTemplate(
       assert,
       "template:bar.loading",
-      "loading",
+      "discourse/templates/loading",
       "fallback with dot"
     );
 
     lookupTemplate(
       assert,
       "template:bar_loading",
-      "loading",
+      "discourse/templates/loading",
       "fallback underscore"
     );
 
@@ -493,61 +539,66 @@ module("Unit | Ember | resolver", function (hooks) {
 
   test("resolves connector templates", function (assert) {
     setTemplates([
-      "javascripts/foo",
-      "javascripts/connectors/foo-bar/baz_qux",
-      "javascripts/connectors/foo-bar/camelCase",
+      "discourse/plugins/my-plugin/discourse/templates/foo",
+      "discourse/plugins/my-plugin/discourse/templates/connectors/foo-bar/baz_qux",
+      "discourse/plugins/my-plugin/discourse/templates/connectors/foo-bar/camelCase",
     ]);
 
     lookupTemplate(
       assert,
       "template:connectors/foo",
-      "javascripts/foo",
-      "looks up in javascripts/ namespace"
+      "discourse/plugins/my-plugin/discourse/templates/foo",
+      "looks up in plugin namespace"
     );
 
     lookupTemplate(
       assert,
       "template:connectors/components/foo",
-      "javascripts/foo",
+      "discourse/plugins/my-plugin/discourse/templates/foo",
       "removes components segment"
     );
 
     lookupTemplate(
       assert,
       "template:connectors/foo-bar/baz-qux",
-      "javascripts/connectors/foo-bar/baz_qux",
+      "discourse/plugins/my-plugin/discourse/templates/connectors/foo-bar/baz_qux",
       "underscores last segment"
     );
 
     lookupTemplate(
       assert,
       "template:connectors/foo-bar/camelCase",
-      "javascripts/connectors/foo-bar/camelCase",
+      "discourse/plugins/my-plugin/discourse/templates/connectors/foo-bar/camelCase",
       "handles camelcase file names"
     );
 
     lookupTemplate(
       assert,
       resolver.normalize("template:connectors/foo-bar/camelCase"),
-      "javascripts/connectors/foo-bar/camelCase",
+      "discourse/plugins/my-plugin/discourse/templates/connectors/foo-bar/camelCase",
       "handles camelcase file names when normalized"
     );
   });
 
   test("returns 'not_found' template when template name cannot be resolved", function (assert) {
-    setTemplates(["not_found"]);
+    setTemplates(["discourse/templates/not_found"]);
 
-    lookupTemplate(assert, "template:foo/bar/baz", "not_found", "");
+    lookupTemplate(
+      assert,
+      "template:foo/bar/baz",
+      "discourse/templates/not_found",
+      ""
+    );
   });
 
   test("resolves templates with 'wizard' prefix", function (assert) {
     setTemplates([
       "wizard/templates/foo",
-      "wizard_bar",
-      "wizard.bar",
+      "discourse/templates/wizard_bar",
+      "discourse/templates/wizard.bar",
       "wizard/templates/bar",
       "wizard/templates/dashboard_general",
-      "wizard-baz-qux",
+      "discourse/templates/wizard-baz-qux",
       "javascripts/wizard/plugin-template",
     ]);
 
@@ -579,7 +630,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:wizard_bar",
-      "wizard_bar",
+      "discourse/templates/wizard_bar",
       "but not when template with the exact underscored name exists"
     );
 
@@ -587,7 +638,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:wizard.bar",
-      "wizard.bar",
+      "discourse/templates/wizard.bar",
       "but not when template with the exact dotted name exists"
     );
 
@@ -601,7 +652,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:wizard-baz/qux",
-      "wizard-baz-qux",
+      "discourse/templates/wizard-baz-qux",
       "also tries dasherized"
     );
   });
@@ -609,7 +660,7 @@ module("Unit | Ember | resolver", function (hooks) {
   test("resolves component templates with 'wizard' prefix to 'wizard/templates/' namespace", function (assert) {
     setTemplates([
       "wizard/templates/components/foo",
-      "components/bar",
+      "discourse/templates/components/bar",
       "wizard/templates/components/bar",
     ]);
 
@@ -625,7 +676,7 @@ module("Unit | Ember | resolver", function (hooks) {
     lookupTemplate(
       assert,
       "template:components/bar",
-      "components/bar",
+      "discourse/templates/components/bar",
       "uses standard match when both exist"
     );
   });
diff --git a/plugins/styleguide/assets/javascripts/discourse/lib/styleguide.js b/plugins/styleguide/assets/javascripts/discourse/lib/styleguide.js
index 8b1610d07d..aac2b772ef 100644
--- a/plugins/styleguide/assets/javascripts/discourse/lib/styleguide.js
+++ b/plugins/styleguide/assets/javascripts/discourse/lib/styleguide.js
@@ -1,3 +1,4 @@
+import DiscourseTemplateMap from "discourse-common/lib/discourse-template-map";
 let _allCategories = null;
 let _sectionsById = {};
 let _notes = {};
@@ -30,7 +31,7 @@ export function allCategories() {
 
   // Find a list of sections based on what templates are available
   // eslint-disable-next-line no-undef
-  Object.keys(Ember.TEMPLATES).forEach((e) => {
+  DiscourseTemplateMap.keys().forEach((e) => {
     let regexp = new RegExp(`styleguide\/(${paths})\/(\\d+)?\\-?([^\\/]+)$`);
     let matches = e.match(regexp);
     if (matches) {