diff --git a/.changeset/famous-monkeys-sort.md b/.changeset/famous-monkeys-sort.md
new file mode 100644
index 000000000000..0c42c9c9119c
--- /dev/null
+++ b/.changeset/famous-monkeys-sort.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': minor
+---
+
+feat: warn on external goto navigation in preparation for SvelteKit 2
diff --git a/packages/kit/src/runtime/app/navigation.js b/packages/kit/src/runtime/app/navigation.js
index 0da8f93e1599..f0256c5b466e 100644
--- a/packages/kit/src/runtime/app/navigation.js
+++ b/packages/kit/src/runtime/app/navigation.js
@@ -16,6 +16,7 @@ export const disableScrollHandling = /* @__PURE__ */ client_method('disable_scro
  *   noScroll?: boolean;
  *   keepFocus?: boolean;
  *   invalidateAll?: boolean;
+ *   external?: boolean;
  *   state?: any
  * }) => Promise<void>}
  * @param {string | URL} url Where to navigate to. Note that if you've set [`config.kit.paths.base`](https://kit.svelte.dev/docs/configuration#paths) and the URL is root-relative, you need to prepend the base path if you want to navigate within the app.
@@ -23,7 +24,8 @@ export const disableScrollHandling = /* @__PURE__ */ client_method('disable_scro
  * @param {boolean} [opts.replaceState] If `true`, will replace the current `history` entry rather than creating a new one with `pushState`
  * @param {boolean} [opts.noScroll] If `true`, the browser will maintain its scroll position rather than scrolling to the top of the page after navigation
  * @param {boolean} [opts.keepFocus] If `true`, the currently focused element will retain focus after navigation. Otherwise, focus will be reset to the body
- * @param {boolean} [invalidateAll] If `true`, all `load` functions of the page will be rerun. See https://kit.svelte.dev/docs/load#rerunning-load-functions for more info on invalidation.
+ * @param {boolean} [opts.invalidateAll] If `true`, all `load` functions of the page will be rerun. See https://kit.svelte.dev/docs/load#rerunning-load-functions for more info on invalidation.
+ * @param {boolean} [opts.external] By default, `goto` will warn on navigation to external URLs for consistency and security reasons (in SvelteKit 2, this will be an error). Set this to `true` to allow navigating to external URLs.
  * @param {any} [opts.state] The state of the new/updated history entry
  * @returns {Promise<void>}
  */
diff --git a/packages/kit/src/runtime/client/client.js b/packages/kit/src/runtime/client/client.js
index 08465d6b5342..9b820c70a9d5 100644
--- a/packages/kit/src/runtime/client/client.js
+++ b/packages/kit/src/runtime/client/client.js
@@ -1376,6 +1376,17 @@ export function create_client(app, target) {
 		},
 
 		goto: (href, opts = {}) => {
+			if (DEV) {
+				if (typeof href === 'string') {
+					href = new URL(href, get_base_uri(document));
+				}
+				if (!opts.external && href.origin !== origin) {
+					console.warn(
+						'Navigating to an external URL using `goto` will be an error in SvelteKit 2 unless the `external` option is set'
+					);
+				}
+			}
+
 			return goto(href, opts, 0);
 		},
 
diff --git a/packages/kit/test/apps/basics/test/cross-platform/client.test.js b/packages/kit/test/apps/basics/test/cross-platform/client.test.js
index 598c6e4c356e..1b52aab21002 100644
--- a/packages/kit/test/apps/basics/test/cross-platform/client.test.js
+++ b/packages/kit/test/apps/basics/test/cross-platform/client.test.js
@@ -147,7 +147,7 @@ test.describe('Navigation lifecycle functions', () => {
 		baseURL
 	}) => {
 		await page.goto('/navigation-lifecycle/before-navigate/prevent-navigation');
-		await app.goto('https://google.de');
+		await app.goto('https://google.de', { external: true });
 		expect(page.url()).toBe(baseURL + '/navigation-lifecycle/before-navigate/prevent-navigation');
 		expect(await page.innerHTML('pre')).toBe('1 true goto');
 	});
@@ -216,7 +216,7 @@ test.describe('Navigation lifecycle functions', () => {
 		await page.goto('/navigation-lifecycle/before-navigate/prevent-navigation');
 		await page.click('h1'); // The browsers block attempts to prevent navigation on a frame that's never had a user gesture.
 
-		await app.goto('https://google.de');
+		await app.goto('https://google.de', { external: true });
 		await app.goto('/navigation-lifecycle/before-navigate/prevent-navigation?x=1');
 
 		expect(await page.innerHTML('pre')).toBe('2 false goto');
diff --git a/packages/kit/test/utils.d.ts b/packages/kit/test/utils.d.ts
index 6ba3c0b8d89f..5ffab4b42b43 100644
--- a/packages/kit/test/utils.d.ts
+++ b/packages/kit/test/utils.d.ts
@@ -13,7 +13,7 @@ export const test: TestType<
 	PlaywrightTestArgs &
 		PlaywrightTestOptions & {
 			app: {
-				goto(url: string, opts?: { replaceState?: boolean }): Promise<void>;
+				goto(url: string, opts?: { replaceState?: boolean; external?: boolean }): Promise<void>;
 				invalidate(url: string): Promise<void>;
 				beforeNavigate(url: URL): void | boolean;
 				afterNavigate(url: URL): void;