diff --git a/.changeset/forty-worms-deliver.md b/.changeset/forty-worms-deliver.md
new file mode 100644
index 000000000000..d9a8a30eb89a
--- /dev/null
+++ b/.changeset/forty-worms-deliver.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[fix] `svelte-kit sync` gracefully handles a nonexistent routes folder
diff --git a/packages/kit/src/core/sync/create_manifest_data/index.js b/packages/kit/src/core/sync/create_manifest_data/index.js
index c55dce642b70..bd4f3c296a98 100644
--- a/packages/kit/src/core/sync/create_manifest_data/index.js
+++ b/packages/kit/src/core/sync/create_manifest_data/index.js
@@ -84,118 +84,120 @@ export default function create_manifest_data({
 	const routes_base = posixify(path.relative(cwd, config.kit.files.routes));
 	const valid_extensions = [...config.extensions, ...config.kit.endpointExtensions];
 
-	list_files(config.kit.files.routes).forEach((file) => {
-		const extension = valid_extensions.find((ext) => file.endsWith(ext));
-		if (!extension) return;
-
-		const id = file
-			.slice(0, -extension.length)
-			.replace(/(?:^|\/)index((?:@[a-zA-Z0-9_-]+)?(?:\.[a-z]+)?)?$/, '$1');
-		const project_relative = `${routes_base}/${file}`;
-
-		const segments = id.split('/');
-		const name = /** @type {string} */ (segments.pop());
-
-		if (name === '__layout.reset') {
-			throw new Error(
-				'__layout.reset has been removed in favour of named layouts: https://kit.svelte.dev/docs/layouts#named-layouts'
-			);
-		}
+	if (fs.existsSync(config.kit.files.routes)) {
+		list_files(config.kit.files.routes).forEach((file) => {
+			const extension = valid_extensions.find((ext) => file.endsWith(ext));
+			if (!extension) return;
 
-		if (name === '__error' || layout_pattern.test(name)) {
-			const dir = segments.join('/');
+			const id = file
+				.slice(0, -extension.length)
+				.replace(/(?:^|\/)index((?:@[a-zA-Z0-9_-]+)?(?:\.[a-z]+)?)?$/, '$1');
+			const project_relative = `${routes_base}/${file}`;
 
-			if (!tree.has(dir)) {
-				tree.set(dir, {
-					error: undefined,
-					layouts: {}
-				});
-			}
+			const segments = id.split('/');
+			const name = /** @type {string} */ (segments.pop());
 
-			const group = /** @type {Node} */ (tree.get(dir));
+			if (name === '__layout.reset') {
+				throw new Error(
+					'__layout.reset has been removed in favour of named layouts: https://kit.svelte.dev/docs/layouts#named-layouts'
+				);
+			}
 
-			if (name === '__error') {
-				group.error = project_relative;
-			} else {
-				const match = /** @type {RegExpMatchArray} */ (layout_pattern.exec(name));
+			if (name === '__error' || layout_pattern.test(name)) {
+				const dir = segments.join('/');
 
-				if (match[1] === DEFAULT) {
-					throw new Error(`${project_relative} cannot use reserved "${DEFAULT}" name`);
+				if (!tree.has(dir)) {
+					tree.set(dir, {
+						error: undefined,
+						layouts: {}
+					});
 				}
 
-				const layout_id = match[1] || DEFAULT;
+				const group = /** @type {Node} */ (tree.get(dir));
+
+				if (name === '__error') {
+					group.error = project_relative;
+				} else {
+					const match = /** @type {RegExpMatchArray} */ (layout_pattern.exec(name));
 
-				const defined = group.layouts[layout_id];
-				if (defined && defined !== default_layout) {
-					throw new Error(
-						`Duplicate layout ${project_relative} already defined at ${defined.file}`
-					);
+					if (match[1] === DEFAULT) {
+						throw new Error(`${project_relative} cannot use reserved "${DEFAULT}" name`);
+					}
+
+					const layout_id = match[1] || DEFAULT;
+
+					const defined = group.layouts[layout_id];
+					if (defined && defined !== default_layout) {
+						throw new Error(
+							`Duplicate layout ${project_relative} already defined at ${defined.file}`
+						);
+					}
+
+					group.layouts[layout_id] = {
+						file: project_relative,
+						name
+					};
 				}
 
-				group.layouts[layout_id] = {
-					file: project_relative,
-					name
-				};
+				return;
+			} else if (dunder_pattern.test(file)) {
+				throw new Error(
+					`Files and directories prefixed with __ are reserved (saw ${project_relative})`
+				);
 			}
 
-			return;
-		} else if (dunder_pattern.test(file)) {
-			throw new Error(
-				`Files and directories prefixed with __ are reserved (saw ${project_relative})`
-			);
-		}
-
-		if (!config.kit.routes(file)) return;
+			if (!config.kit.routes(file)) return;
 
-		if (/\]\[/.test(id)) {
-			throw new Error(`Invalid route ${project_relative} — parameters must be separated`);
-		}
+			if (/\]\[/.test(id)) {
+				throw new Error(`Invalid route ${project_relative} — parameters must be separated`);
+			}
 
-		if (count_occurrences('[', id) !== count_occurrences(']', id)) {
-			throw new Error(`Invalid route ${project_relative} — brackets are unbalanced`);
-		}
+			if (count_occurrences('[', id) !== count_occurrences(']', id)) {
+				throw new Error(`Invalid route ${project_relative} — brackets are unbalanced`);
+			}
 
-		if (!units.has(id)) {
-			units.set(id, {
-				id,
-				pattern: parse_route_id(id).pattern,
-				segments: id
-					.split('/')
-					.filter(Boolean)
-					.map((segment) => {
-						/** @type {Part[]} */
-						const parts = [];
-						segment.split(/\[(.+?)\]/).map((content, i) => {
-							const dynamic = !!(i % 2);
-
-							if (!content) return;
-
-							parts.push({
-								content,
-								dynamic,
-								rest: dynamic && content.startsWith('...'),
-								type: (dynamic && content.split('=')[1]) || null
+			if (!units.has(id)) {
+				units.set(id, {
+					id,
+					pattern: parse_route_id(id).pattern,
+					segments: id
+						.split('/')
+						.filter(Boolean)
+						.map((segment) => {
+							/** @type {Part[]} */
+							const parts = [];
+							segment.split(/\[(.+?)\]/).map((content, i) => {
+								const dynamic = !!(i % 2);
+
+								if (!content) return;
+
+								parts.push({
+									content,
+									dynamic,
+									rest: dynamic && content.startsWith('...'),
+									type: (dynamic && content.split('=')[1]) || null
+								});
 							});
-						});
-						return parts;
-					}),
-				page: undefined,
-				endpoint: undefined
-			});
-		}
+							return parts;
+						}),
+					page: undefined,
+					endpoint: undefined
+				});
+			}
 
-		const unit = /** @type {Unit} */ (units.get(id));
+			const unit = /** @type {Unit} */ (units.get(id));
 
-		if (config.extensions.find((ext) => file.endsWith(ext))) {
-			const { layouts, errors } = trace(project_relative, file, tree, config.extensions);
-			unit.page = {
-				a: layouts.concat(project_relative),
-				b: errors
-			};
-		} else {
-			unit.endpoint = project_relative;
-		}
-	});
+			if (config.extensions.find((ext) => file.endsWith(ext))) {
+				const { layouts, errors } = trace(project_relative, file, tree, config.extensions);
+				unit.page = {
+					a: layouts.concat(project_relative),
+					b: errors
+				};
+			} else {
+				unit.endpoint = project_relative;
+			}
+		});
+	}
 
 	/** @type {string[]} */
 	const components = [];
diff --git a/packages/kit/src/core/sync/create_manifest_data/index.spec.js b/packages/kit/src/core/sync/create_manifest_data/index.spec.js
index 022b7e4e7d41..ac197bee9e3a 100644
--- a/packages/kit/src/core/sync/create_manifest_data/index.spec.js
+++ b/packages/kit/src/core/sync/create_manifest_data/index.spec.js
@@ -128,6 +128,12 @@ test('creates routes with layout', () => {
 	]);
 });
 
+test('succeeds when routes does not exist', () => {
+	const { components, routes } = create('samples/basic/routes');
+	assert.equal(components, ['layout.svelte', 'error.svelte']);
+	assert.equal(routes, []);
+});
+
 // TODO some characters will need to be URL-encoded in the filename
 test('encodes invalid characters', () => {
 	const { components, routes } = create('samples/encoding');