diff --git a/.changeset/large-birds-repair.md b/.changeset/large-birds-repair.md
new file mode 100644
index 000000000..669ab6b86
--- /dev/null
+++ b/.changeset/large-birds-repair.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Markdown file.url now respects `trailingSlash` and `base`
diff --git a/packages/astro/src/core/build/generate.ts b/packages/astro/src/core/build/generate.ts
index e76d51ca3..d68f8faf3 100644
--- a/packages/astro/src/core/build/generate.ts
+++ b/packages/astro/src/core/build/generate.ts
@@ -179,7 +179,7 @@ async function generatePath(
 	// If a base path was provided, append it to the site URL. This ensures that
 	// all injected scripts and links are referenced relative to the site and subpath.
 	const site =
-		astroConfig.base && astroConfig.base !== './'
+		astroConfig.base !== '/'
 			? joinPaths(astroConfig.site?.toString() || 'http://localhost/', astroConfig.base)
 			: astroConfig.site;
 	const links = createLinkStylesheetElementSet(linkIds.reverse(), site);
diff --git a/packages/astro/src/core/config.ts b/packages/astro/src/core/config.ts
index 57b45ef1b..de947530d 100644
--- a/packages/astro/src/core/config.ts
+++ b/packages/astro/src/core/config.ts
@@ -94,8 +94,8 @@ export const AstroConfigSchema = z.object({
 	base: z
 		.string()
 		.optional()
-		.default('./')
-		.transform((val) => (val ? appendForwardSlash(trimSlashes(val)) : val)),
+		.default('/')
+		.transform((val) => appendForwardSlash(trimSlashes(val))),
 	trailingSlash: z
 		.union([z.literal('always'), z.literal('never'), z.literal('ignore')])
 		.optional()
diff --git a/packages/astro/src/vite-plugin-astro-server/index.ts b/packages/astro/src/vite-plugin-astro-server/index.ts
index d21fa7e8e..0fdb8705b 100644
--- a/packages/astro/src/vite-plugin-astro-server/index.ts
+++ b/packages/astro/src/vite-plugin-astro-server/index.ts
@@ -114,8 +114,7 @@ async function handle404Response(
 		// HACK: redirect without the base path for assets in publicDir
 		const redirectTo =
 			req.method === 'GET' &&
-			config.base &&
-			config.base !== './' &&
+			config.base !== '/' &&
 			pathname.startsWith(config.base) &&
 			pathname.replace(config.base, '/');
 
diff --git a/packages/astro/src/vite-plugin-markdown/index.ts b/packages/astro/src/vite-plugin-markdown/index.ts
index 231977002..105ff47e0 100644
--- a/packages/astro/src/vite-plugin-markdown/index.ts
+++ b/packages/astro/src/vite-plugin-markdown/index.ts
@@ -78,13 +78,18 @@ export default function markdown({ config }: AstroPluginOptions): Plugin {
 			// Return the file's JS representation, including all Markdown
 			// frontmatter and a deferred `import() of the compiled markdown content.
 			if (id.endsWith(`.md${MARKDOWN_IMPORT_FLAG}`)) {
-				const sitePathname = config.site
-					? appendForwardSlash(new URL(config.base, config.site).pathname)
-					: '/';
+				const sitePathname = appendForwardSlash(
+					config.site ? new URL(config.base, config.site).pathname : config.base
+				);
+
 				const fileId = id.replace(MARKDOWN_IMPORT_FLAG, '');
-				const fileUrl = fileId.includes('/pages/')
-					? fileId.replace(/^.*\/pages\//, sitePathname).replace(/(\/index)?\.md$/, '')
+				let fileUrl = fileId.includes('/pages/')
+					? fileId.replace(/^.*?\/pages\//, sitePathname).replace(/(\/index)?\.md$/, '')
 					: undefined;
+				if (fileUrl && config.trailingSlash === 'always') {
+					fileUrl = appendForwardSlash(fileUrl);
+				}
+
 				const source = await fs.promises.readFile(fileId, 'utf8');
 				const { data: frontmatter } = matter(source);
 				return {
diff --git a/packages/astro/test/astro-markdown-url.test.js b/packages/astro/test/astro-markdown-url.test.js
new file mode 100644
index 000000000..54ce8bfba
--- /dev/null
+++ b/packages/astro/test/astro-markdown-url.test.js
@@ -0,0 +1,100 @@
+import { expect } from 'chai';
+import cheerio from 'cheerio';
+import { loadFixture } from './test-utils.js';
+
+describe('Astro Markdown URL', () => {
+	describe('With subpath', () => {
+		const baseUrl = `/my-cool-base/docs/pages/how-to-make-a-page`;
+
+		it('trailingSlash: always', async () => {
+			let fixture = await loadFixture({
+				root: './fixtures/astro-markdown-url/',
+				outDir: new URL('./fixtures/astro-markdown-url/with-subpath-always/', import.meta.url),
+				base: '/my-cool-base',
+				trailingSlash: 'always',
+			});
+			await fixture.build();
+
+			const html = await fixture.readFile('/index.html');
+			const $ = cheerio.load(html);
+
+			expect($('#url').attr('href')).to.equal(baseUrl + '/');
+		});
+
+		it('trailingSlash: never', async () => {
+			let fixture = await loadFixture({
+				root: './fixtures/astro-markdown-url/',
+				outDir: new URL('./fixtures/astro-markdown-url/with-subpath-never/', import.meta.url),
+				base: '/my-cool-base',
+				trailingSlash: 'never',
+			});
+			await fixture.build();
+
+			const html = await fixture.readFile('/index.html');
+			const $ = cheerio.load(html);
+
+			expect($('#url').attr('href')).to.equal(baseUrl);
+		});
+
+		it('trailingSlash: ignore', async () => {
+			let fixture = await loadFixture({
+				root: './fixtures/astro-markdown-url/',
+				outDir: new URL('./fixtures/astro-markdown-url/with-subpath-ignore/', import.meta.url),
+				base: '/my-cool-base',
+				trailingSlash: 'ignore',
+			});
+			await fixture.build();
+
+			const html = await fixture.readFile('/index.html');
+			const $ = cheerio.load(html);
+
+			expect($('#url').attr('href')).to.equal(baseUrl);
+		});
+	});
+
+	describe('Without subpath', () => {
+		const baseUrl = `/docs/pages/how-to-make-a-page`;
+
+		it('trailingSlash: always', async () => {
+			let fixture = await loadFixture({
+				root: './fixtures/astro-markdown-url/',
+				outDir: new URL('./fixtures/astro-markdown-url/without-subpath-always/', import.meta.url),
+				trailingSlash: 'always',
+			});
+			await fixture.build();
+
+			const html = await fixture.readFile('/index.html');
+			const $ = cheerio.load(html);
+
+			expect($('#url').attr('href')).to.equal(baseUrl + '/');
+		});
+
+		it('trailingSlash: never', async () => {
+			let fixture = await loadFixture({
+				root: './fixtures/astro-markdown-url/',
+				outDir: new URL('./fixtures/astro-markdown-url/without-subpath-never/', import.meta.url),
+				trailingSlash: 'never',
+			});
+			await fixture.build();
+
+			const html = await fixture.readFile('/index.html');
+			const $ = cheerio.load(html);
+
+			expect($('#url').attr('href')).to.equal(baseUrl);
+		});
+
+		it('trailingSlash: ignore', async () => {
+			let fixture = await loadFixture({
+				root: './fixtures/astro-markdown-url/',
+				outDir: new URL('./fixtures/astro-markdown-url/without-subpath-ignore/', import.meta.url),
+				trailingSlash: 'ignore',
+			});
+			await fixture.build();
+
+			const html = await fixture.readFile('/index.html');
+			const $ = cheerio.load(html);
+
+			expect($('#url').attr('href')).to.equal(baseUrl);
+		});
+	});
+});
diff --git a/packages/astro/test/fixtures/astro-markdown-url/.gitignore b/packages/astro/test/fixtures/astro-markdown-url/.gitignore
new file mode 100644
index 000000000..dad853294
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-url/.gitignore
@@ -0,0 +1,6 @@
+with-subpath-always/
+with-subpath-never/
+with-subpath-ignore/
+without-subpath-always/
+without-subpath-never/
+without-subpath-ignore/
diff --git a/packages/astro/test/fixtures/astro-markdown-url/package.json b/packages/astro/test/fixtures/astro-markdown-url/package.json
new file mode 100644
index 000000000..341814951
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-url/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@test/astro-markdown-url",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/astro/test/fixtures/astro-markdown-url/src/pages/docs/pages/how-to-make-a-page.md b/packages/astro/test/fixtures/astro-markdown-url/src/pages/docs/pages/how-to-make-a-page.md
new file mode 100644
index 000000000..901c35955
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-url/src/pages/docs/pages/how-to-make-a-page.md
@@ -0,0 +1,5 @@
+---
+title: How to make a page
+---
+
+Test
diff --git a/packages/astro/test/fixtures/astro-markdown-url/src/pages/index.astro b/packages/astro/test/fixtures/astro-markdown-url/src/pages/index.astro
new file mode 100644
index 000000000..c6a77b0e1
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-url/src/pages/index.astro
@@ -0,0 +1,5 @@
+---
+import * as page from './docs/pages/how-to-make-a-page.md'
+---
+
+<a id="url" href={page.url}>{page.frontmatter.title}</a>
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 4a470892d..baa7a59ca 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -860,6 +860,12 @@ importers:
     dependencies:
       astro: link:../../../..
 
+  packages/astro/test/fixtures/astro-markdown-url:
+    specifiers:
+      astro: workspace:*
+    dependencies:
+      astro: link:../../..
+
   packages/astro/test/fixtures/astro-page-directory-url:
     specifiers:
       astro: workspace:*