diff --git a/README.md b/README.md
index 5cd3427637..3876fac378 100644
--- a/README.md
+++ b/README.md
@@ -560,24 +560,25 @@ To disable a rule for an entire `.gjs`/`.gts` file, use a regular ESLint file-le
 
 ### Testing
 
-| Name                                                                                                   | Description                                                                                              | 💼 | 🔧 | 💡 |
-| :----------------------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------- | :- | :- | :- |
-| [no-current-route-name](docs/rules/no-current-route-name.md)                                           | disallow usage of the `currentRouteName()` test helper                                                   |    |    |    |
-| [no-ember-testing-in-module-scope](docs/rules/no-ember-testing-in-module-scope.md)                     | disallow use of `Ember.testing` in module scope                                                          | ✅  |    |    |
-| [no-invalid-test-waiters](docs/rules/no-invalid-test-waiters.md)                                       | disallow incorrect usage of test waiter APIs                                                             | ✅  |    |    |
-| [no-legacy-test-waiters](docs/rules/no-legacy-test-waiters.md)                                         | disallow the use of the legacy test waiter APIs                                                          | ✅  |    |    |
-| [no-noop-setup-on-error-in-before](docs/rules/no-noop-setup-on-error-in-before.md)                     | disallows using no-op setupOnerror in `before` or `beforeEach`                                           | ✅  | 🔧 |    |
-| [no-pause-test](docs/rules/no-pause-test.md)                                                           | disallow usage of the `pauseTest` helper in tests                                                        | ✅  |    |    |
-| [no-replace-test-comments](docs/rules/no-replace-test-comments.md)                                     | disallow 'Replace this with your real tests' comments in test files                                      |    |    |    |
-| [no-restricted-resolver-tests](docs/rules/no-restricted-resolver-tests.md)                             | disallow the use of patterns that use the restricted resolver in tests                                   | ✅  |    |    |
-| [no-settled-after-test-helper](docs/rules/no-settled-after-test-helper.md)                             | disallow usage of `await settled()` right after test helper that calls it internally                     | ✅  | 🔧 |    |
-| [no-test-and-then](docs/rules/no-test-and-then.md)                                                     | disallow usage of the `andThen` test wait helper                                                         | ✅  |    |    |
-| [no-test-import-export](docs/rules/no-test-import-export.md)                                           | disallow importing of "-test.js" in a test file and exporting from a test file                           | ✅  |    |    |
-| [no-test-module-for](docs/rules/no-test-module-for.md)                                                 | disallow usage of `moduleFor`, `moduleForComponent`, etc                                                 | ✅  |    |    |
-| [no-test-support-import](docs/rules/no-test-support-import.md)                                         | disallow importing of "test-support" files in production code.                                           | ✅  |    |    |
-| [no-test-this-render](docs/rules/no-test-this-render.md)                                               | disallow usage of the `this.render` in tests, recommending to use @ember/test-helpers' `render` instead. | ✅  |    |    |
-| [prefer-ember-test-helpers](docs/rules/prefer-ember-test-helpers.md)                                   | enforce usage of `@ember/test-helpers` methods over native window methods                                | ✅  |    |    |
-| [require-valid-css-selector-in-test-helpers](docs/rules/require-valid-css-selector-in-test-helpers.md) | disallow using invalid CSS selectors in test helpers                                                     | ✅  | 🔧 |    |
+| Name                                                                                                   | Description                                                                                                     | 💼 | 🔧 | 💡 |
+| :----------------------------------------------------------------------------------------------------- | :-------------------------------------------------------------------------------------------------------------- | :- | :- | :- |
+| [no-current-route-name](docs/rules/no-current-route-name.md)                                           | disallow usage of the `currentRouteName()` test helper                                                          |    |    |    |
+| [no-ember-testing-in-module-scope](docs/rules/no-ember-testing-in-module-scope.md)                     | disallow use of `Ember.testing` in module scope                                                                 | ✅  |    |    |
+| [no-invalid-test-waiters](docs/rules/no-invalid-test-waiters.md)                                       | disallow incorrect usage of test waiter APIs                                                                    | ✅  |    |    |
+| [no-legacy-test-waiters](docs/rules/no-legacy-test-waiters.md)                                         | disallow the use of the legacy test waiter APIs                                                                 | ✅  |    |    |
+| [no-noop-setup-on-error-in-before](docs/rules/no-noop-setup-on-error-in-before.md)                     | disallows using no-op setupOnerror in `before` or `beforeEach`                                                  | ✅  | 🔧 |    |
+| [no-pause-test](docs/rules/no-pause-test.md)                                                           | disallow usage of the `pauseTest` helper in tests                                                               | ✅  |    |    |
+| [no-replace-test-comments](docs/rules/no-replace-test-comments.md)                                     | disallow 'Replace this with your real tests' comments in test files                                             |    |    |    |
+| [no-restricted-resolver-tests](docs/rules/no-restricted-resolver-tests.md)                             | disallow the use of patterns that use the restricted resolver in tests                                          | ✅  |    |    |
+| [no-settled-after-test-helper](docs/rules/no-settled-after-test-helper.md)                             | disallow usage of `await settled()` right after test helper that calls it internally                            | ✅  | 🔧 |    |
+| [no-test-and-then](docs/rules/no-test-and-then.md)                                                     | disallow usage of the `andThen` test wait helper                                                                | ✅  |    |    |
+| [no-test-import-export](docs/rules/no-test-import-export.md)                                           | disallow importing of "-test.js" in a test file and exporting from a test file                                  | ✅  |    |    |
+| [no-test-module-for](docs/rules/no-test-module-for.md)                                                 | disallow usage of `moduleFor`, `moduleForComponent`, etc                                                        | ✅  |    |    |
+| [no-test-support-import](docs/rules/no-test-support-import.md)                                         | disallow importing of "test-support" files in production code.                                                  | ✅  |    |    |
+| [no-test-this-render](docs/rules/no-test-this-render.md)                                               | disallow usage of the `this.render` in tests, recommending to use @ember/test-helpers' `render` instead.        | ✅  |    |    |
+| [no-test-this-set-get](docs/rules/no-test-this-set-get.md)                                             | disallow usage of `this.set`, `this.get`, `this.setProperties`, and `this.getProperties` in `.gjs`/`.gts` tests |    |    |    |
+| [prefer-ember-test-helpers](docs/rules/prefer-ember-test-helpers.md)                                   | enforce usage of `@ember/test-helpers` methods over native window methods                                       | ✅  |    |    |
+| [require-valid-css-selector-in-test-helpers](docs/rules/require-valid-css-selector-in-test-helpers.md) | disallow using invalid CSS selectors in test helpers                                                            | ✅  | 🔧 |    |
 
 <!-- end auto-generated rules list -->
 
diff --git a/docs/rules/no-test-this-set-get.md b/docs/rules/no-test-this-set-get.md
new file mode 100644
index 0000000000..a7045cd32c
--- /dev/null
+++ b/docs/rules/no-test-this-set-get.md
@@ -0,0 +1,79 @@
+# ember/no-test-this-set-get
+
+<!-- end auto-generated rule header -->
+
+In `.gjs`/`.gts` tests, the `<template>` tag has access to the surrounding scope, so any value used by a test's template can be a local variable (optionally tracked) instead of being assigned to the test context (`this`). As a result, the legacy `this.set`, `this.get`, `this.setProperties`, and `this.getProperties` helpers are no longer recommended in template-tag tests.
+
+## Rule Details
+
+This rule disallows the following in `.gjs` and `.gts` test files:
+
+- `this.set(...)`, `this.get(...)`, `this.setProperties(...)`, `this.getProperties(...)` (including the computed `this["set"](...)` form).
+- Calls to `set`, `get`, `setProperties`, and `getProperties` when imported from `@ember/object` (including aliased imports).
+
+It does not flag these calls in `.js`/`.ts` tests, or in non-test files.
+
+## Examples
+
+Examples of **incorrect** code for this rule (in a `*-test.gjs` or `*-test.gts` file):
+
+```gjs
+test('it renders', async function (assert) {
+  this.set('name', 'Zoey');
+  await render(<template>{{this.name}}</template>);
+});
+```
+
+```gjs
+test('it reads', function (assert) {
+  const value = this.get('name');
+});
+```
+
+```gjs
+test('it sets many', function (assert) {
+  this.setProperties({ name: 'Zoey', age: 4 });
+});
+```
+
+```gjs
+test('it reads many', function (assert) {
+  const { name, age } = this.getProperties('name', 'age');
+});
+```
+
+```gjs
+import { set } from '@ember/object';
+
+test('it sets', function (assert) {
+  set(obj, 'name', 'Zoey');
+});
+```
+
+Examples of **correct** code for this rule (in a `*-test.gjs` or `*-test.gts` file):
+
+```gjs
+test('it renders', async function (assert) {
+  const name = 'Zoey';
+  await render(<template>{{name}}</template>);
+});
+```
+
+```gjs
+import { tracked } from '@glimmer/tracking';
+
+class State {
+  @tracked name = 'Zoey';
+}
+
+test('it renders', async function (assert) {
+  const state = new State();
+  await render(<template>{{state.name}}</template>);
+  state.name = 'Tomster';
+});
+```
+
+## References
+
+- [RFC 779: First-Class Component Templates](https://github.com/emberjs/rfcs/pull/779)
+- The legacy [`set`](https://api.emberjs.com/ember/release/functions/@ember%2Fobject/set), [`get`](https://api.emberjs.com/ember/release/functions/@ember%2Fobject/get), `setProperties`, and `getProperties` helpers from `@ember/object`.
diff --git a/lib/rules/no-test-this-set-get.js b/lib/rules/no-test-this-set-get.js
new file mode 100644
index 0000000000..914bf67f0a
--- /dev/null
+++ b/lib/rules/no-test-this-set-get.js
@@ -0,0 +1,102 @@
+'use strict';
+
+const emberUtils = require('../utils/ember');
+const types = require('../utils/types');
+const { getImportIdentifier } = require('../utils/import');
+
+const DISALLOWED_METHODS = ['set', 'get', 'setProperties', 'getProperties'];
+const DISALLOWED_METHOD_SET = new Set(DISALLOWED_METHODS);
+
+function makeThisErrorMessage(methodName) {
+  return `Do not use \`this.${methodName}()\` in gjs/gts tests. Use tracked state or local variables in the test \`<template>\` instead.`;
+}
+
+function makeImportedErrorMessage(methodName) {
+  return `Do not use \`${methodName}()\` from \`@ember/object\` in gjs/gts tests. Use tracked state or local variables in the test \`<template>\` instead.`;
+}
+
+function isGjsOrGtsTestFile(fileName) {
+  return (
+    emberUtils.isTestFile(fileName) && (fileName.endsWith('.gjs') || fileName.endsWith('.gts'))
+  );
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description:
+        'disallow usage of `this.set`, `this.get`, `this.setProperties`, and `this.getProperties` in `.gjs`/`.gts` tests',
+      category: 'Testing',
+      recommended: false,
+      recommendedGjs: false,
+      recommendedGts: false,
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/no-test-this-set-get.md',
+    },
+    fixable: null,
+    schema: [],
+  },
+
+  makeErrorMessage: makeThisErrorMessage,
+  makeThisErrorMessage,
+  makeImportedErrorMessage,
+
+  create(context) {
+    if (!isGjsOrGtsTestFile(context.filename)) {
+      return {};
+    }
+
+    // Map from local identifier name -> the original `@ember/object` export name.
+    const importedNames = new Map();
+
+    return {
+      ImportDeclaration(node) {
+        if (node.source.value !== '@ember/object') {
+          return;
+        }
+        for (const original of DISALLOWED_METHODS) {
+          const localName = getImportIdentifier(node, '@ember/object', original);
+          if (localName) {
+            importedNames.set(localName, original);
+          }
+        }
+      },
+
+      CallExpression(node) {
+        const { callee } = node;
+
+        // Flag `this.set(...)`, `this.get(...)`, etc., including the computed
+        // form `this["set"](...)`.
+        if (callee.type === 'MemberExpression' && types.isThisExpression(callee.object)) {
+          let propertyName;
+          if (!callee.computed && types.isIdentifier(callee.property)) {
+            propertyName = callee.property.name;
+          } else if (callee.computed && types.isStringLiteral(callee.property)) {
+            propertyName = callee.property.value;
+          }
+          if (propertyName && DISALLOWED_METHOD_SET.has(propertyName)) {
+            context.report({
+              node,
+              message: makeThisErrorMessage(propertyName),
+            });
+            return;
+          }
+        }
+
+        // Flag calls to `set`/`get`/`setProperties`/`getProperties` when
+        // imported from `@ember/object`.
+        if (types.isIdentifier(callee) && importedNames.has(callee.name)) {
+          context.report({
+            node,
+            message: makeImportedErrorMessage(importedNames.get(callee.name)),
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tests/lib/rules/no-test-this-set-get.js b/tests/lib/rules/no-test-this-set-get.js
new file mode 100644
index 0000000000..94c20a4cdb
--- /dev/null
+++ b/tests/lib/rules/no-test-this-set-get.js
@@ -0,0 +1,163 @@
+'use strict';
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const rule = require('../../../lib/rules/no-test-this-set-get');
+const RuleTester = require('eslint').RuleTester;
+
+const { makeThisErrorMessage, makeImportedErrorMessage } = rule;
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+const TEST_FILE_NAME_GJS = 'some-test.gjs';
+const TEST_FILE_NAME_GTS = 'some-test.gts';
+const TEST_FILE_NAME_JS = 'some-test.js';
+
+const ruleTester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 2022,
+    sourceType: 'module',
+  },
+});
+
+ruleTester.run('no-test-this-set-get', rule, {
+  valid: [
+    // Not flagged in plain .js test files (only gjs/gts).
+    {
+      filename: TEST_FILE_NAME_JS,
+      code: 'test("x", function () { this.set("foo", 1); });',
+    },
+    {
+      filename: TEST_FILE_NAME_JS,
+      code: 'test("x", function () { this.get("foo"); });',
+    },
+    {
+      filename: TEST_FILE_NAME_JS,
+      code: 'import { set } from "@ember/object"; test("x", function () { set(obj, "foo", 1); });',
+    },
+    // Not flagged outside of test files.
+    {
+      filename: 'some-component.gjs',
+      code: 'function f() { this.set("foo", 1); }',
+    },
+    {
+      filename: 'some-component.gjs',
+      code: 'import { set } from "@ember/object"; function f() { set(obj, "foo", 1); }',
+    },
+    // Not flagged for unrelated methods on `this`.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { this.owner.lookup("foo"); });',
+    },
+    // Not flagged for free `set`/`get`/... calls when NOT imported from `@ember/object`.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { set(obj, "foo", 1); });',
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'test("x", function () { get(obj, "foo"); });',
+    },
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'import { set } from "some-other-module"; test("x", function () { set(obj, "foo", 1); });',
+    },
+    // Not flagged for unrelated method on something else.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { foo.set("a", 1); });',
+    },
+    // Not flagged for unrelated imports from `@ember/object`.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'import { computed } from "@ember/object"; test("x", function () { computed(); });',
+    },
+  ],
+  invalid: [
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { this.set("foo", 1); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('set'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'test("x", function () { this.set("foo", 1); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('set'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { this.get("foo"); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('get'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'test("x", function () { this.get("foo"); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('get'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { this.setProperties({ foo: 1 }); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('setProperties'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'test("x", function () { this.getProperties("foo", "bar"); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('getProperties'), type: 'CallExpression' }],
+    },
+    // Computed `this["set"](...)` form.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'test("x", function () { this["set"]("foo", 1); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('set'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'test("x", function () { this["getProperties"]("foo"); });',
+      output: null,
+      errors: [{ message: makeThisErrorMessage('getProperties'), type: 'CallExpression' }],
+    },
+    // Imported from `@ember/object`.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'import { set } from "@ember/object"; test("x", function () { set(obj, "foo", 1); });',
+      output: null,
+      errors: [{ message: makeImportedErrorMessage('set'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'import { get } from "@ember/object"; test("x", function () { get(obj, "foo"); });',
+      output: null,
+      errors: [{ message: makeImportedErrorMessage('get'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'import { setProperties } from "@ember/object"; test("x", function () { setProperties(obj, { foo: 1 }); });',
+      output: null,
+      errors: [{ message: makeImportedErrorMessage('setProperties'), type: 'CallExpression' }],
+    },
+    {
+      filename: TEST_FILE_NAME_GTS,
+      code: 'import { getProperties } from "@ember/object"; test("x", function () { getProperties(obj, "foo", "bar"); });',
+      output: null,
+      errors: [{ message: makeImportedErrorMessage('getProperties'), type: 'CallExpression' }],
+    },
+    // Aliased import.
+    {
+      filename: TEST_FILE_NAME_GJS,
+      code: 'import { set as emberSet } from "@ember/object"; test("x", function () { emberSet(obj, "foo", 1); });',
+      output: null,
+      errors: [{ message: makeImportedErrorMessage('set'), type: 'CallExpression' }],
+    },
+  ],
+});