diff --git a/docs/rules/isolated-functions.md b/docs/rules/isolated-functions.md
new file mode 100644
index 0000000000..642b8af6c3
--- /dev/null
+++ b/docs/rules/isolated-functions.md
@@ -0,0 +1,271 @@
+# Prevent usage of variables from outside the scope of isolated functions
+
+💼🚫 This rule is enabled in the ✅ `recommended` [config](https://github.com/sindresorhus/eslint-plugin-unicorn#recommended-config). This rule is _disabled_ in the ☑️ `unopinionated` [config](https://github.com/sindresorhus/eslint-plugin-unicorn#recommended-config).
+
+<!-- end auto-generated rule header -->
+<!-- Do not manually modify this header. Run: `npm run fix:eslint-docs` -->
+
+Some functions need to be isolated from their surrounding scope due to execution context constraints. For example, functions passed to [`makeSynchronous()`](https://github.com/sindresorhus/make-synchronous) are executed in a worker or subprocess and cannot access variables from outside their scope. This rule helps identify when functions are using external variables that may cause runtime errors.
+
+Common scenarios where functions must be isolated:
+
+- Functions passed to `makeSynchronous()` (executed in worker)
+- Functions that will be serialized via `Function.prototype.toString()`
+- Server actions or other remote execution contexts
+- Functions with specific JSDoc annotations
+
+By default, this rule uses ESLint's language options globals and allows global variables (like `console`, `fetch`, etc.) in isolated functions, but prevents usage of variables from the surrounding scope.
+
+## Examples
+
+```js
+import makeSynchronous from 'make-synchronous';
+
+const url = 'https://example.com';
+
+const getText = makeSynchronous(async () => {
+	const response = await fetch(url); // ❌ 'url' is not defined in isolated function scope
+	return response.text();
+});
+
+// ✅ Define all variables within isolated function's scope
+const getText = makeSynchronous(async () => {
+	const url = 'https://example.com'; // Variable defined within function scope
+	const response = await fetch(url);
+	return response.text();
+});
+
+// ✅ Alternative: Pass as parameter
+const getText = makeSynchronous(async (url) => { // Variable passed as parameter
+	const response = await fetch(url);
+	return response.text();
+});
+
+console.log(getText('https://example.com'));
+```
+
+```js
+const foo = 'hi';
+
+/** @isolated */
+function abc() {
+	return foo.slice(); // ❌ 'foo' is not defined in isolated function scope
+}
+
+// ✅
+/** @isolated */
+function abc() {
+	const foo = 'hi'; // Variable defined within function scope
+	return foo.slice();
+}
+```
+
+## Options
+
+Type: `object`
+
+### functions
+
+Type: `string[]`\
+Default: `['makeSynchronous']`
+
+Array of function names that create isolated execution contexts. Functions passed as arguments to these functions will be considered isolated.
+
+### selectors
+
+Type: `string[]`\
+Default: `[]`
+
+Array of [ESLint selectors](https://eslint.org/docs/developer-guide/selectors) to identify isolated functions. Useful for custom naming conventions or framework-specific patterns.
+
+```js
+{
+	'unicorn/isolated-functions': [
+		'error',
+		{
+			selectors: [
+				'FunctionDeclaration[id.name=/lambdaHandler.*/]'
+			]
+		}
+	]
+}
+```
+
+### comments
+
+Type: `string[]`\
+Default: `['@isolated']`
+
+Array of comment strings that mark functions as isolated. Functions with inline, block, or JSDoc comments tagged with these strings will be considered isolated. (Definition of "tagged": either the comment consists solely of the tag, or starts with it, and has an explanation following a hyphen, like `// @isolated - this function will be stringified`).
+
+```js
+{
+	'unicorn/isolated-functions': [
+		'error',
+		{
+			comments: [
+				'@isolated',
+				'@remote'
+			]
+		}
+	]
+}
+```
+
+### overrideGlobals
+
+Type: `object`\
+Default: `undefined` (uses ESLint's language options globals)
+
+Controls how global variables are handled. When not specified, uses ESLint's language options globals. When specified as an object, each key is a global variable name and the value controls its behavior:
+
+- `'readonly'`: Global variable is allowed but cannot be written to
+- `'writable'`: Global variable is allowed and can be read/written
+- `'off'`: Global variable is not allowed
+
+```js
+{
+	'unicorn/isolated-functions': [
+		'error',
+		{
+			overrideGlobals: {
+				console: 'writable',     // Allowed and writable
+				fetch: 'readonly',       // Allowed but readonly
+				process: 'off'           // Not allowed
+			}
+		}
+	]
+}
+```
+
+## Examples
+
+### Custom function names
+
+```js
+{
+	'unicorn/isolated-functions': [
+		'error',
+		{
+			functions: [
+				'makeSynchronous',
+				'createWorker',
+				'serializeFunction'
+			]
+		}
+	]
+}
+```
+
+### Lambda function naming convention
+
+```js
+{
+	'unicorn/isolated-functions': [
+		'error',
+		{
+			selectors: [
+				'FunctionDeclaration[id.name=/lambdaHandler.*/]'
+			]
+		}
+	]
+}
+```
+
+```js
+const foo = 'hi';
+
+function lambdaHandlerFoo() { // ❌ Will be flagged as isolated
+	return foo.slice();
+}
+
+function someOtherFunction() { // ✅ Not flagged
+	return foo.slice();
+}
+
+createLambda({
+	name: 'fooLambda',
+	code: lambdaHandlerFoo.toString(), // Function will be serialized
+});
+```
+
+### Default behavior (using ESLint's language options)
+
+```js
+// Uses ESLint's language options globals by default
+makeSynchronous(async () => {
+	console.log('Starting...'); // ✅ Allowed if console is in language options
+	const response = await fetch('https://api.example.com'); // ✅ Allowed if fetch is in language options
+	return response.text();
+});
+```
+
+### Allowing specific globals
+
+```js
+{
+	'unicorn/isolated-functions': [
+		'error',
+		{
+			overrideGlobals: {
+				console: 'writable',     // Allowed and writable
+				fetch: 'readonly',       // Allowed but readonly
+				URL: 'readonly'          // Allowed but readonly
+			}
+		}
+	]
+}
+```
+
+```js
+// ✅ All globals used are explicitly allowed
+makeSynchronous(async () => {
+	console.log('Starting...'); // ✅ Allowed global
+	const response = await fetch('https://api.example.com'); // ✅ Allowed global
+	const url = new URL(response.url); // ✅ Allowed global
+	return response.text();
+});
+
+makeSynchronous(async () => {
+	const response = await fetch('https://api.example.com', {
+		headers: {
+			'Authorization': `Bearer ${process.env.API_TOKEN}` // ❌ 'process' is not in allowed globals
+		}
+	});
+
+	const url = new URL(response.url);
+
+	return response.text();
+});
+
+// ❌ Attempting to write to readonly global
+makeSynchronous(async () => {
+	fetch = null; // ❌ 'fetch' is readonly
+	console.log('Starting...');
+});
+```
+
+### Predefined global variables
+
+To enable a predefined set of globals, use the [`globals` package](https://npmjs.com/package/globals) similarly to how you would use it in `languageOptions` (see [ESLint docs on globals](https://eslint.org/docs/latest/use/configure/language-options#predefined-global-variables)):
+
+```js
+import globals from 'globals'
+
+export default [
+	{
+		rules: {
+			'unicorn/isolated-functions': [
+				'error',
+				{
+					globals: {
+						...globals.builtin,
+						...globals.applescript,
+						...globals.greasemonkey,
+					},
+				},
+			],
+		},
+	},
+]
+```
diff --git a/readme.md b/readme.md
index eaf3113b9c..3dc0b9edde 100644
--- a/readme.md
+++ b/readme.md
@@ -73,6 +73,7 @@ export default [
 | [explicit-length-check](docs/rules/explicit-length-check.md)                                     | Enforce explicitly comparing the `length` or `size` property of a value.                                                                                                                                          | ✅    | 🔧 | 💡 |
 | [filename-case](docs/rules/filename-case.md)                                                     | Enforce a case style for filenames.                                                                                                                                                                               | ✅    |    |    |
 | [import-style](docs/rules/import-style.md)                                                       | Enforce specific import styles per module.                                                                                                                                                                        | ✅ ☑️ |    |    |
+| [isolated-functions](docs/rules/isolated-functions.md)                                           | Prevent usage of variables from outside the scope of isolated functions.                                                                                                                                          | ✅    |    |    |
 | [new-for-builtins](docs/rules/new-for-builtins.md)                                               | Enforce the use of `new` for all builtins, except `String`, `Number`, `Boolean`, `Symbol` and `BigInt`.                                                                                                           | ✅ ☑️ | 🔧 | 💡 |
 | [no-abusive-eslint-disable](docs/rules/no-abusive-eslint-disable.md)                             | Enforce specifying rules to disable in `eslint-disable` comments.                                                                                                                                                 | ✅ ☑️ |    |    |
 | [no-accessor-recursion](docs/rules/no-accessor-recursion.md)                                     | Disallow recursive access to `this` within getters and setters.                                                                                                                                                   | ✅ ☑️ |    |    |
diff --git a/rules/index.js b/rules/index.js
index 0bb7fb36eb..f28bfe7015 100644
--- a/rules/index.js
+++ b/rules/index.js
@@ -16,6 +16,7 @@ export {default as 'expiring-todo-comments'} from './expiring-todo-comments.js';
 export {default as 'explicit-length-check'} from './explicit-length-check.js';
 export {default as 'filename-case'} from './filename-case.js';
 export {default as 'import-style'} from './import-style.js';
+export {default as 'isolated-functions'} from './isolated-functions.js';
 export {default as 'new-for-builtins'} from './new-for-builtins.js';
 export {default as 'no-abusive-eslint-disable'} from './no-abusive-eslint-disable.js';
 export {default as 'no-accessor-recursion'} from './no-accessor-recursion.js';
diff --git a/rules/isolated-functions.js b/rules/isolated-functions.js
new file mode 100644
index 0000000000..4f38c53e8c
--- /dev/null
+++ b/rules/isolated-functions.js
@@ -0,0 +1,199 @@
+import globals from 'globals';
+import esquery from 'esquery';
+import {functionTypes} from './ast/index.js';
+
+const MESSAGE_ID_EXTERNALLY_SCOPED_VARIABLE = 'externally-scoped-variable';
+const messages = {
+	[MESSAGE_ID_EXTERNALLY_SCOPED_VARIABLE]: 'Variable {{name}} not defined in scope of isolated function. Function is isolated because: {{reason}}.',
+};
+
+const parsedEsquerySelectors = new Map();
+const parseEsquerySelector = selector => {
+	if (!parsedEsquerySelectors.has(selector)) {
+		parsedEsquerySelectors.set(selector, esquery.parse(selector));
+	}
+
+	return parsedEsquerySelectors.get(selector);
+};
+
+/** @type {{functions: string[], selectors: string[], comments: string[], overrideGlobals?: import('eslint').Linter.Globals}} */
+const defaultOptions = {
+	functions: ['makeSynchronous'],
+	selectors: [],
+	comments: ['@isolated'],
+	overrideGlobals: {},
+};
+
+/** @param {import('eslint').Rule.RuleContext} context */
+const create = context => {
+	const {sourceCode} = context;
+	/** @type {typeof defaultOptions} */
+	const options = {
+		...defaultOptions,
+		...context.options[0],
+	};
+
+	options.comments = options.comments.map(comment => comment.toLowerCase());
+
+	const allowedGlobals = {
+		...(globals[`es${context.languageOptions.ecmaVersion}`] ?? globals.builtins),
+		...context.languageOptions.globals,
+		...options.overrideGlobals,
+	};
+
+	/** @param {import('estree').Node} node */
+	const checkForExternallyScopedVariables = node => {
+		let reason = reasonForBeingIsolatedFunction(node);
+		if (!reason) {
+			return;
+		}
+
+		const nodeScope = sourceCode.getScope(node);
+
+		// `through`: "The array of references which could not be resolved in this scope" https://eslint.org/docs/latest/extend/scope-manager-interface#scope-interface
+		for (const reference of nodeScope.through) {
+			const {identifier} = reference;
+			if (identifier.name in allowedGlobals && allowedGlobals[identifier.name] !== 'off') {
+				if (reference.isReadOnly()) {
+					continue;
+				}
+
+				const globalsValue = allowedGlobals[identifier.name];
+				const isGlobalWritable = globalsValue === true || globalsValue === 'writable' || globalsValue === 'writeable';
+				if (isGlobalWritable) {
+					continue;
+				}
+
+				reason += ' (global variable is not writable)';
+			}
+
+			// Could consider checking for typeof operator here, like in no-undef?
+
+			context.report({
+				node: identifier,
+				messageId: MESSAGE_ID_EXTERNALLY_SCOPED_VARIABLE,
+				data: {name: identifier.name, reason},
+			});
+		}
+	};
+
+	const isComment = token => token?.type === 'Block' || token?.type === 'Line';
+
+	/**
+	 Find a comment on this node or its parent, in cases where the node passed is part of a variable or export declaration.
+	 @param {import('estree').Node} node
+	 */
+	const findComment = node => {
+		let previousToken = sourceCode.getTokenBefore(node, {includeComments: true});
+		let commentableNode = node;
+		while (
+			!isComment(previousToken)
+			&& (commentableNode.parent.type === 'VariableDeclarator'
+				|| commentableNode.parent.type === 'VariableDeclaration'
+				|| commentableNode.parent.type === 'ExportNamedDeclaration'
+				|| commentableNode.parent.type === 'ExportDefaultDeclaration')
+		) {
+			commentableNode = commentableNode.parent;
+			previousToken = sourceCode.getTokenBefore(commentableNode, {includeComments: true});
+		}
+
+		if (isComment(previousToken)) {
+			return previousToken.value;
+		}
+	};
+
+	/**
+	 Find the string "reason" that a function (node) should be considered isolated. For passing in to `context.report(...)` when out-of-scope variables are found. Returns undefined if the function should not be considered isolated.
+	 @param {import('estree').Node & {parent?: import('estree').Node}} node
+	 */
+	const reasonForBeingIsolatedFunction = node => {
+		if (options.comments.length > 0) {
+			let previousComment = findComment(node);
+
+			if (previousComment) {
+				previousComment = previousComment
+					.replace(/(?:\*\s*)*/, '') // JSDoc comments like `/** @isolated */` are parsed into `* @isolated`. And `/**\n * @isolated */` is parsed into `*\n * @isolated`
+					.trim()
+					.toLowerCase();
+				const match = options.comments.find(comment => previousComment === comment || previousComment.startsWith(`${comment} - `) || previousComment.startsWith(`${comment} -- `));
+				if (match) {
+					return `follows comment ${JSON.stringify(match)}`;
+				}
+			}
+		}
+
+		if (
+			options.functions.length > 0
+			&& node.parent.type === 'CallExpression'
+			&& node.parent.arguments.includes(node)
+			&& node.parent.callee.type === 'Identifier'
+			&& options.functions.includes(node.parent.callee.name)
+		) {
+			return `callee of function named ${JSON.stringify(node.parent.callee.name)}`;
+		}
+
+		if (options.selectors.length > 0) {
+			const ancestors = sourceCode.getAncestors(node);
+			const matchedSelector = options.selectors.find(selector => esquery.matches(node, parseEsquerySelector(selector), ancestors));
+			if (matchedSelector) {
+				return `matches selector ${JSON.stringify(matchedSelector)}`;
+			}
+		}
+	};
+
+	context.on(
+		functionTypes.map(type => `${type}:exit`),
+		checkForExternallyScopedVariables,
+	);
+};
+
+/** @type {import('json-schema').JSONSchema7[]} */
+const schema = [
+	{
+		type: 'object',
+		additionalProperties: false,
+		properties: {
+			overrideGlobals: {
+				additionalProperties: {
+					anyOf: [{type: 'boolean'}, {type: 'string', enum: ['readonly', 'writable', 'writeable', 'off']}],
+				},
+			},
+			functions: {
+				type: 'array',
+				uniqueItems: true,
+				items: {
+					type: 'string',
+				},
+			},
+			selectors: {
+				type: 'array',
+				uniqueItems: true,
+				items: {
+					type: 'string',
+				},
+			},
+			comments: {
+				type: 'array',
+				uniqueItems: true,
+				items: {
+					type: 'string',
+				},
+			},
+		},
+	},
+];
+
+/** @type {import('eslint').Rule.RuleModule} */
+export default {
+	create,
+	meta: {
+		type: 'problem',
+		docs: {
+			description: 'Prevent usage of variables from outside the scope of isolated functions.',
+			recommended: true,
+		},
+		schema,
+		defaultOptions: [defaultOptions],
+		messages,
+	},
+};
diff --git a/test/isolated-functions.js b/test/isolated-functions.js
new file mode 100644
index 0000000000..a493caf65c
--- /dev/null
+++ b/test/isolated-functions.js
@@ -0,0 +1,278 @@
+import outdent from 'outdent';
+import {getTester} from './utils/test.js';
+
+const {test} = getTester(import.meta);
+
+const error = data => ({messageId: 'externally-scoped-variable', data});
+const fooInMakeSynchronousError = error({name: 'foo', reason: 'callee of function named "makeSynchronous"'});
+
+test({
+	/** @type {import('eslint').RuleTester.ValidTestCase[]} */
+	valid: [
+		{
+			name: 'variable defined in scope of isolated function',
+			code: outdent`
+				makeSynchronous(() => {
+					const foo = 'hi';
+					return foo.slice();
+				});
+			`,
+		},
+		{
+			name: 'variable defined as parameter of isolated function',
+			code: outdent`
+				makeSynchronous(foo => {
+					return foo.slice();
+				});
+			`,
+		},
+		{
+			name: 'inner function can access outer function parameters',
+			code: outdent`
+				/** @isolated */
+				function abc () {
+					const foo = 'hi';
+					const slice = () => foo.slice();
+					return slice();
+				}
+			`,
+		},
+		{
+			name: 'variable defined as parameter of isolated function (async)',
+			code: outdent`
+				makeSynchronous(async function (foo) {
+					return foo.slice();
+				});
+			`,
+		},
+		{
+			name: 'default global variables come from language options',
+			code: 'makeSynchronous(() => process.env.MAP ? new Map() : new URL("https://example.com"))',
+		},
+		{
+			name: 'global Array',
+			code: 'makeSynchronous(() => new Array())',
+		},
+		{
+			name: 'global Array w overrideGlobals: {} still works',
+			code: 'makeSynchronous(() => new Array())',
+			options: [{overrideGlobals: {}}],
+		},
+		{
+			name: 'can implicitly allow global variables from language options',
+			languageOptions: {globals: {foo: true}},
+			code: outdent`
+				makeSynchronous(function () {
+					return foo.slice();
+				});
+			`,
+		},
+		{
+			name: 'allow global variables separate from language options',
+			languageOptions: {globals: {abc: true}},
+			options: [{overrideGlobals: {foo: true}}],
+			code: outdent`
+				makeSynchronous(function () {
+					return foo.slice();
+				});
+			`,
+		},
+	],
+	/** @type {import('eslint').RuleTester.InvalidTestCase[]} */
+	invalid: [
+		{
+			name: 'out of scope variable under makeSynchronous (arrow function)',
+			code: outdent`
+				const foo = 'hi';
+				makeSynchronous(() => foo.slice());
+			`,
+			errors: [fooInMakeSynchronousError],
+		},
+		{
+			name: 'out of scope variable under makeSynchronous (async arrow function)',
+			code: outdent`
+				const foo = 'hi';
+				makeSynchronous(async () => foo.slice());
+			`,
+			errors: [fooInMakeSynchronousError],
+		},
+		{
+			name: 'out of scope variable under makeSynchronous (function expression)',
+			code: outdent`
+				const foo = 'hi';
+				makeSynchronous(function () {
+					return foo.slice();
+				});
+			`,
+			errors: [fooInMakeSynchronousError],
+		},
+		{
+			name: 'out of scope variable under makeSynchronous (async function expression)',
+			code: outdent`
+				const foo = 'hi';
+				makeSynchronous(async function () {
+					return foo.slice();
+				});
+			`,
+			errors: [fooInMakeSynchronousError],
+		},
+		{
+			name: 'out of scope variable under makeSynchronous (named function expression)',
+			code: outdent`
+				const foo = 'hi';
+				makeSynchronous(function abc () {
+					return foo.slice();
+				});
+			`,
+			errors: [fooInMakeSynchronousError],
+		},
+		{
+			name: 'out of scope variable under makeSynchronous (named async function expression)',
+			code: outdent`
+				const foo = 'hi';
+				makeSynchronous(async function abc () {
+					return foo.slice();
+				});
+			`,
+			errors: [fooInMakeSynchronousError],
+		},
+		{
+			name: '@isolated comment on function declaration',
+			code: outdent`
+				const foo = 'hi';
+				/** @isolated */
+				function abc () {
+					return foo.slice();
+				}
+			`,
+			errors: [error({name: 'foo', reason: 'follows comment "@isolated"'})],
+		},
+		{
+			name: '@isolated comment on arrow function',
+			code: outdent`
+				const foo = 'hi';
+				/** @isolated */
+				const abc = () => foo.slice();
+			`,
+			errors: [error({name: 'foo', reason: 'follows comment "@isolated"'})],
+		},
+		{
+			name: '@isolated comments with explanations',
+			code: outdent`
+				const foo = 'hi';
+				// @isolated - explanation
+				const abc1 = () => foo.slice();
+
+				// @isolated -- explanation
+				const abc2 = () => foo.slice();
+			`,
+			errors: [
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+			],
+		},
+		{
+			name: '@isolated block comments',
+			code: outdent`
+				const foo = 'hi';
+				/* @isolated */
+				const abc1 = () => foo.slice();
+
+				/** @isolated */
+				const abc2 = () => foo.slice();
+
+				/**
+				 * @isolated
+				 */
+				const abc3 = () => foo.slice();
+			`,
+			errors: [
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+			],
+		},
+		{
+			name: '@isolated inline comment',
+			code: outdent`
+				const foo = 'hi';
+				// @isolated
+				const abc = () => foo.slice();
+			`,
+			errors: [error({name: 'foo', reason: 'follows comment "@isolated"'})],
+		},
+		{
+			name: '@isolated comment on exports',
+			code: outdent`
+				const foo = 'hi';
+
+				// @isolated
+				export const abc = () => foo.slice();
+
+				// @isolated
+				export default () => foo.slice();
+			`,
+			errors: [
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+				error({name: 'foo', reason: 'follows comment "@isolated"'}),
+			],
+		},
+		{
+			name: 'individual global variables can be explicitly disallowed',
+			options: [{overrideGlobals: {URLSearchParams: 'readonly', URL: 'off'}}],
+			code: outdent`
+				makeSynchronous(function () {
+					return new URL('https://example.com?') + new URLSearchParams({a: 'b'}).toString();
+				});
+			`,
+			errors: [error({name: 'URL', reason: 'callee of function named "makeSynchronous"'})],
+		},
+		{
+			name: 'check globals writability',
+			code: outdent`
+				makeSynchronous(function () {
+					location = new URL('https://example.com');
+					process = {env: {}};
+					process.env.FOO = 'bar';
+				});
+			`,
+			errors: [
+				// Only one error, `location = new URL('https://example.com')` and `process.env.FOO = 'bar'` are fine, the problem is `process = {...}`.
+				error({
+					name: 'process',
+					reason: 'callee of function named "makeSynchronous" (global variable is not writable)',
+				}),
+			],
+		},
+		{
+			name: 'make a function isolated by a selector',
+			// In this case, we're imagining some naming convention for lambda functions that will be created via `fn.toString()`
+			options: [{selectors: ['FunctionDeclaration[id.name=/lambdaHandler.*/]']}],
+			code: outdent`
+				const foo = 'hi';
+
+				function lambdaHandlerFoo() {
+					return foo.slice();
+				}
+
+				function someOtherFunction() {
+					return foo.slice();
+				}
+
+				createLambda({
+					name: 'fooLambda',
+					code: lambdaHandlerFoo.toString(),
+				});
+			`,
+			errors: [
+				error({name: 'foo', reason: 'matches selector "FunctionDeclaration[id.name=/lambdaHandler.*/]"'}),
+			],
+		},
+		{
+			name: 'can explicitly turn off ecmascript globals',
+			code: 'makeSynchronous(() => new Array())',
+			options: [{overrideGlobals: {Array: 'off'}}],
+			errors: [error({name: 'Array', reason: 'callee of function named "makeSynchronous"'})],
+		},
+	],
+});