diff --git a/.changeset/wicked-hairs-rescue.md b/.changeset/wicked-hairs-rescue.md
new file mode 100644
index 000000000..6b4da6b39
--- /dev/null
+++ b/.changeset/wicked-hairs-rescue.md
@@ -0,0 +1,5 @@
+---
+"astro": patch
+---
+
+Add `mdx` extension to default generated Tailwind config.
diff --git a/examples/with-tailwindcss/tailwind.config.cjs b/examples/with-tailwindcss/tailwind.config.cjs
index dc0ae5c8f..49971da79 100644
--- a/examples/with-tailwindcss/tailwind.config.cjs
+++ b/examples/with-tailwindcss/tailwind.config.cjs
@@ -1,5 +1,5 @@
 module.exports = {
-	content: ['./src/**/*.{astro,html,js,jsx,md,svelte,ts,tsx,vue}'],
+	content: ['./src/**/*.{astro,html,js,jsx,md,mdx,svelte,ts,tsx,vue}'],
 	theme: {
 		extend: {},
 	},
diff --git a/packages/astro/e2e/fixtures/tailwindcss/tailwind.config.js b/packages/astro/e2e/fixtures/tailwindcss/tailwind.config.js
index 7aeb483c1..a7a741ba3 100644
--- a/packages/astro/e2e/fixtures/tailwindcss/tailwind.config.js
+++ b/packages/astro/e2e/fixtures/tailwindcss/tailwind.config.js
@@ -1,7 +1,7 @@
 const path = require('path');
 
 module.exports = {
-	content: [path.join(__dirname, 'src/**/*.{astro,html,js,jsx,md,svelte,ts,tsx,vue}')],
+	content: [path.join(__dirname, 'src/**/*.{astro,html,js,jsx,md,mdx,svelte,ts,tsx,vue}')],
 	theme: {
 		extend: {
 			colors: {
diff --git a/packages/astro/src/core/add/index.ts b/packages/astro/src/core/add/index.ts
index 4062e59e5..d6ee73791 100644
--- a/packages/astro/src/core/add/index.ts
+++ b/packages/astro/src/core/add/index.ts
@@ -41,7 +41,7 @@ const ALIASES = new Map([
 const ASTRO_CONFIG_STUB = `import { defineConfig } from 'astro/config';\n\nexport default defineConfig({});`;
 const TAILWIND_CONFIG_STUB = `/** @type {import('tailwindcss').Config} */
 module.exports = {
-	content: ['./src/**/*.{astro,html,js,jsx,md,svelte,ts,tsx,vue}'],
+	content: ['./src/**/*.{astro,html,js,jsx,md,mdx,svelte,ts,tsx,vue}'],
 	theme: {
 		extend: {},
 	},
diff --git a/packages/astro/test/fixtures/tailwindcss/tailwind.config.js b/packages/astro/test/fixtures/tailwindcss/tailwind.config.js
index 7aeb483c1..a7a741ba3 100644
--- a/packages/astro/test/fixtures/tailwindcss/tailwind.config.js
+++ b/packages/astro/test/fixtures/tailwindcss/tailwind.config.js
@@ -1,7 +1,7 @@
 const path = require('path');
 
 module.exports = {
-	content: [path.join(__dirname, 'src/**/*.{astro,html,js,jsx,md,svelte,ts,tsx,vue}')],
+	content: [path.join(__dirname, 'src/**/*.{astro,html,js,jsx,md,mdx,svelte,ts,tsx,vue}')],
 	theme: {
 		extend: {
 			colors: {