diff --git a/.changeset/healthy-rabbits-grab.md b/.changeset/healthy-rabbits-grab.md
new file mode 100644
index 00000000000..1bde31b8081
--- /dev/null
+++ b/.changeset/healthy-rabbits-grab.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/starlight': patch
+---
+
+Fix sidebar highlighting and navigation buttons for pages with path containing non-ASCII characters
diff --git a/packages/starlight/__tests__/sidebar/navigation-unicode.test.ts b/packages/starlight/__tests__/sidebar/navigation-unicode.test.ts
new file mode 100644
index 00000000000..5e280af7ddf
--- /dev/null
+++ b/packages/starlight/__tests__/sidebar/navigation-unicode.test.ts
@@ -0,0 +1,117 @@
+import { describe, expect, test, vi } from 'vitest';
+import { getSidebar } from '../../utils/navigation';
+
+vi.mock('astro:content', async () =>
+	(await import('../test-utils')).mockedAstroContent({
+		docs: [
+			['index.mdx', { title: 'Home Page' }],
+			['environmental-impact.md', { title: 'Eco-friendly docs' }],
+			['reference/configuration.mdx', { title: 'Config Reference' }],
+			['reference/frontmatter.md', { title: 'Frontmatter Reference' }],
+			// @ts-expect-error — Using a slug not present in Starlight docs site
+			['api/v1/用户.md', { title: 'Path with non-ASCII characters' }],
+			['guides/components.mdx', { title: 'Components' }],
+		],
+	})
+);
+
+describe('getSidebar', () => {
+	test('matches current page when path contains non-ascii characters', () => {
+		expect(getSidebar('/api/v1/%E7%94%A8%E6%88%B7', undefined)).toMatchInlineSnapshot(`
+			[
+			  {
+			    "attrs": {},
+			    "badge": undefined,
+			    "href": "/",
+			    "isCurrent": false,
+			    "label": "Home",
+			    "type": "link",
+			  },
+			  {
+			    "badge": undefined,
+			    "collapsed": false,
+			    "entries": [
+			      {
+			        "attrs": {},
+			        "badge": {
+			          "text": "New",
+			          "variant": "success",
+			        },
+			        "href": "/intro/",
+			        "isCurrent": false,
+			        "label": "Introduction",
+			        "type": "link",
+			      },
+			      {
+			        "attrs": {},
+			        "badge": {
+			          "text": "Deprecated",
+			          "variant": "default",
+			        },
+			        "href": "/next-steps/",
+			        "isCurrent": false,
+			        "label": "Next Steps",
+			        "type": "link",
+			      },
+			      {
+			        "attrs": {
+			          "class": "showcase-link",
+			          "target": "_blank",
+			        },
+			        "badge": undefined,
+			        "href": "/showcase/",
+			        "isCurrent": false,
+			        "label": "Showcase",
+			        "type": "link",
+			      },
+			    ],
+			    "label": "Start Here",
+			    "type": "group",
+			  },
+			  {
+			    "badge": {
+			      "text": "Experimental",
+			      "variant": "default",
+			    },
+			    "collapsed": false,
+			    "entries": [
+			      {
+			        "attrs": {},
+			        "badge": undefined,
+			        "href": "/reference/configuration/",
+			        "isCurrent": false,
+			        "label": "Config Reference",
+			        "type": "link",
+			      },
+			      {
+			        "attrs": {},
+			        "badge": undefined,
+			        "href": "/reference/frontmatter/",
+			        "isCurrent": false,
+			        "label": "Frontmatter Reference",
+			        "type": "link",
+			      },
+			    ],
+			    "label": "Reference",
+			    "type": "group",
+			  },
+			  {
+			    "badge": undefined,
+			    "collapsed": false,
+			    "entries": [
+			      {
+			        "attrs": {},
+			        "badge": undefined,
+			        "href": "/api/v1/用户/",
+			        "isCurrent": true,
+			        "label": "Path with non-ASCII characters",
+			        "type": "link",
+			      },
+			    ],
+			    "label": "API v1",
+			    "type": "group",
+			  },
+			]
+		`);
+	});
+});
diff --git a/packages/starlight/utils/navigation.ts b/packages/starlight/utils/navigation.ts
index 5710f553206..1e74932f56e 100644
--- a/packages/starlight/utils/navigation.ts
+++ b/packages/starlight/utils/navigation.ts
@@ -135,7 +135,7 @@ function makeLink(
 	attrs?: LinkHTMLAttributes
 ): Link {
 	if (!isAbsolute(href)) href = pathWithBase(href);
-	const isCurrent = href === ensureTrailingSlash(currentPathname);
+	const isCurrent = encodeURI(href) === ensureTrailingSlash(currentPathname);
 	return { type: 'link', label, href, isCurrent, badge, attrs: attrs ?? {} };
 }