diff --git a/.changeset/tall-adults-film.md b/.changeset/tall-adults-film.md
new file mode 100644
index 000000000000..647d5e91cf05
--- /dev/null
+++ b/.changeset/tall-adults-film.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': major
+---
+
+add support for svelte.config.ts
diff --git a/packages/kit/src/core/config/fixtures/typescript/svelte.config.ts b/packages/kit/src/core/config/fixtures/typescript/svelte.config.ts
new file mode 100644
index 000000000000..ff8b4c56321a
--- /dev/null
+++ b/packages/kit/src/core/config/fixtures/typescript/svelte.config.ts
@@ -0,0 +1 @@
+export default {};
diff --git a/packages/kit/src/core/config/index.js b/packages/kit/src/core/config/index.js
index 7d4817fce5dc..fc2160f46d8b 100644
--- a/packages/kit/src/core/config/index.js
+++ b/packages/kit/src/core/config/index.js
@@ -2,6 +2,8 @@ import fs from 'node:fs';
 import path from 'node:path';
 import * as url from 'node:url';
 import options from './options.js';
+import pkg from 'typescript';
+const { transpileModule } = pkg;
 
 /**
  * Loads the template (src/app.html by default) and validates that it has the
@@ -56,26 +58,48 @@ export function load_error_page(config) {
 }
 
 /**
- * Loads and validates svelte.config.js
+ * Loads and validates svelte.config.js or svelte.config.ts
  * @param {{ cwd?: string }} options
  * @returns {Promise<import('types').ValidatedConfig>}
  */
 export async function load_config({ cwd = process.cwd() } = {}) {
-	const config_file = path.join(cwd, 'svelte.config.js');
+	const js_config_file = path.join(cwd, 'svelte.config.js');
+	const ts_config_file = path.join(cwd, 'svelte.config.ts');
 
-	if (!fs.existsSync(config_file)) {
-		return process_config({}, { cwd });
+	if (fs.existsSync(js_config_file)) {
+		const config = await import(`${url.pathToFileURL(js_config_file).href}?ts=${Date.now()}`);
+		return process_config(config.default, { cwd });
 	}
 
-	const config = await import(`${url.pathToFileURL(config_file).href}?ts=${Date.now()}`);
+	if (fs.existsSync(ts_config_file)) {
+		const config = await load_ts_config(ts_config_file);
+		return process_config(config.default, { cwd });
+	}
+
+	return process_config({}, { cwd });
+}
 
+/**
+ * Loads and transpiles the TypeScript configuration file
+ * @param {string} ts_config_file
+ * @returns {Promise<import('@sveltejs/kit').Config>}
+ */
+async function load_ts_config(ts_config_file) {
 	try {
-		return process_config(config.default, { cwd });
+		const ts_code = fs.readFileSync(ts_config_file, 'utf-8');
+		const js_code = transpileModule(ts_code, {
+			compilerOptions: { module: 99, target: 99 }
+		}).outputText;
+
+		const config = await import(
+			`data:text/javascript;base64,${Buffer.from(js_code).toString('base64')}`
+		);
+		return config;
 	} catch (e) {
 		const error = /** @type {Error} */ (e);
 
 		// redact the stack trace — it's not helpful to users
-		error.stack = `Could not load svelte.config.js: ${error.message}\n`;
+		error.stack = `Could not load svelte.config.ts: ${error.message}\n`;
 		throw error;
 	}
 }
@@ -110,7 +134,7 @@ function process_config(config, { cwd = process.cwd() } = {}) {
 export function validate_config(config) {
 	if (typeof config !== 'object') {
 		throw new Error(
-			'svelte.config.js must have a configuration object as its default export. See https://kit.svelte.dev/docs/configuration'
+			'svelte.config.js or svelte.config.ts must have a configuration object as its default export. See https://kit.svelte.dev/docs/configuration'
 		);
 	}
 
diff --git a/packages/kit/src/core/config/index.spec.js b/packages/kit/src/core/config/index.spec.js
index e5639defc4c2..da39ae39bc48 100644
--- a/packages/kit/src/core/config/index.spec.js
+++ b/packages/kit/src/core/config/index.spec.js
@@ -360,6 +360,18 @@ test('load default config (esm)', async () => {
 	expect(config).toEqual(defaults);
 });
 
+test('load default typescript config (esm)', async () => {
+	const cwd = join(__dirname, 'fixtures/typescript');
+
+	const config = await load_config({ cwd });
+	remove_keys(config, ([, v]) => typeof v === 'function');
+
+	const defaults = get_defaults(cwd + '/');
+	defaults.kit.version.name = config.kit.version.name;
+
+	expect(config).toEqual(defaults);
+});
+
 test('errors on loading config with incorrect default export', async () => {
 	let message = null;
 
@@ -372,6 +384,6 @@ test('errors on loading config with incorrect default export', async () => {
 
 	assert.equal(
 		message,
-		'svelte.config.js must have a configuration object as its default export. See https://kit.svelte.dev/docs/configuration'
+		'svelte.config.js or svelte.config.ts must have a configuration object as its default export. See https://kit.svelte.dev/docs/configuration'
 	);
 });
diff --git a/packages/kit/types/index.d.ts b/packages/kit/types/index.d.ts
index e3bf549b2407..91d447e829f0 100644
--- a/packages/kit/types/index.d.ts
+++ b/packages/kit/types/index.d.ts
@@ -1840,7 +1840,7 @@ declare module '@sveltejs/kit' {
 	class Redirect_1 {
 		
 		constructor(status: 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308, location: string);
-		status: 301 | 302 | 303 | 307 | 308 | 300 | 304 | 305 | 306;
+		status: 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308;
 		location: string;
 	}
 }