diff --git a/packages/astro/src/@types/astro.ts b/packages/astro/src/@types/astro.ts
index b43a31dfec..156bbbb586 100644
--- a/packages/astro/src/@types/astro.ts
+++ b/packages/astro/src/@types/astro.ts
@@ -978,6 +978,7 @@ export interface AstroConfig extends z.output<typeof AstroConfigSchema> {
 }
 
 export interface ContentEntryType {
+	name: string;
 	extensions: string[];
 	getEntryInfo(params: { fileUrl: URL; contents: string }): Promise<{
 		data: Record<string, unknown>;
diff --git a/packages/astro/src/content/index.ts b/packages/astro/src/content/index.ts
index f12106b0aa..67e55e48da 100644
--- a/packages/astro/src/content/index.ts
+++ b/packages/astro/src/content/index.ts
@@ -1,6 +1,11 @@
 export { attachContentServerListeners } from './server-listeners.js';
 export { createContentTypesGenerator } from './types-generator.js';
-export { contentObservable, getContentPaths, getDotAstroTypeReference } from './utils.js';
+export {
+	contentObservable,
+	getContentPaths,
+	getDotAstroTypeReference,
+	hasMdContentEntryTypeOverride,
+} from './utils.js';
 export { astroContentAssetPropagationPlugin } from './vite-plugin-content-assets.js';
 export { astroContentImportPlugin } from './vite-plugin-content-imports.js';
 export { astroContentVirtualModPlugin } from './vite-plugin-content-virtual-mod.js';
diff --git a/packages/astro/src/content/utils.ts b/packages/astro/src/content/utils.ts
index 81aab319e1..26e68834ee 100644
--- a/packages/astro/src/content/utils.ts
+++ b/packages/astro/src/content/utils.ts
@@ -7,6 +7,7 @@ import { ErrorPayload as ViteErrorPayload, normalizePath, ViteDevServer } from '
 import { z } from 'zod';
 import { AstroConfig, AstroSettings } from '../@types/astro.js';
 import { AstroError, AstroErrorData } from '../core/errors/index.js';
+import { MARKDOWN_CONTENT_ENTRY_TYPE_NAME } from '../vite-plugin-markdown/content-entry-type.js';
 import { CONTENT_TYPES_FILE } from './consts.js';
 
 export const collectionConfigParser = z.object({
@@ -347,3 +348,11 @@ function search(fs: typeof fsMod, srcDir: URL) {
 	}
 	return { exists: false, url: paths[0] };
 }
+
+export function hasMdContentEntryTypeOverride(settings: Pick<AstroSettings, 'contentEntryTypes'>) {
+	return settings.contentEntryTypes.some(
+		(contentEntryType) =>
+			contentEntryType.name !== MARKDOWN_CONTENT_ENTRY_TYPE_NAME &&
+			contentEntryType.extensions.includes('.md')
+	);
+}
diff --git a/packages/astro/src/vite-plugin-markdown/content-entry-type.ts b/packages/astro/src/vite-plugin-markdown/content-entry-type.ts
index 01a67e033b..b8ed28f36f 100644
--- a/packages/astro/src/vite-plugin-markdown/content-entry-type.ts
+++ b/packages/astro/src/vite-plugin-markdown/content-entry-type.ts
@@ -2,7 +2,10 @@ import { fileURLToPath } from 'node:url';
 import { ContentEntryType } from '../@types/astro.js';
 import { parseFrontmatter } from '../content/utils.js';
 
+export const MARKDOWN_CONTENT_ENTRY_TYPE_NAME = 'astro:markdown';
+
 export const markdownContentEntryType: ContentEntryType = {
+	name: MARKDOWN_CONTENT_ENTRY_TYPE_NAME,
 	extensions: ['.md'],
 	async getEntryInfo({ fileUrl, contents }: { fileUrl: URL; contents: string }) {
 		const parsed = parseFrontmatter(contents, fileURLToPath(fileUrl));
diff --git a/packages/astro/src/vite-plugin-markdown/index.ts b/packages/astro/src/vite-plugin-markdown/index.ts
index 746bfde369..39f5d1903a 100644
--- a/packages/astro/src/vite-plugin-markdown/index.ts
+++ b/packages/astro/src/vite-plugin-markdown/index.ts
@@ -10,6 +10,7 @@ import type { Plugin } from 'vite';
 import { normalizePath } from 'vite';
 import type { AstroSettings } from '../@types/astro';
 import { getContentPaths } from '../content/index.js';
+import { hasMdContentEntryTypeOverride } from '../content/index.js';
 import { AstroError, AstroErrorData, MarkdownError } from '../core/errors/index.js';
 import type { LogOptions } from '../core/logger/core.js';
 import { warn } from '../core/logger/core.js';
@@ -66,6 +67,15 @@ export default function markdown({ settings, logging }: AstroPluginOptions): Plu
 		async load(id) {
 			if (isMarkdownFile(id)) {
 				const { fileId, fileUrl } = getFileInfo(id, settings.config);
+				if (
+					// Integrations can override the Markdown parser for content collections.
+					// If an override is present, skip this file.
+					fileId.startsWith(getContentPaths(settings.config).contentDir.pathname) &&
+					hasMdContentEntryTypeOverride(settings)
+				) {
+					return;
+				}
+
 				const rawFile = await fs.promises.readFile(fileId, 'utf-8');
 				const raw = safeMatter(rawFile, id);
 				const renderResult = await renderMarkdown(raw.content, {
diff --git a/packages/integrations/markdoc/src/index.ts b/packages/integrations/markdoc/src/index.ts
index ed260563b0..9778ef40e5 100644
--- a/packages/integrations/markdoc/src/index.ts
+++ b/packages/integrations/markdoc/src/index.ts
@@ -6,13 +6,16 @@ import { parseFrontmatter } from './utils.js';
 import { fileURLToPath } from 'node:url';
 import fs from 'node:fs';
 
+const DEFAULT_MARKDOC_EXTS = ['.mdoc', '.md'];
+
 export default function markdoc(): AstroIntegration {
 	return {
 		name: '@astrojs/markdoc',
 		hooks: {
 			'astro:config:setup': async ({ updateConfig, config, addContentEntryType, command }: any) => {
 				const contentEntryType = {
-					extensions: ['.mdoc'],
+					name: 'astro:markdoc',
+					extensions: DEFAULT_MARKDOC_EXTS,
 					async getEntryInfo({ fileUrl, contents }: { fileUrl: URL; contents: string }) {
 						const parsed = parseFrontmatter(contents, fileURLToPath(fileUrl));
 						return {
@@ -34,7 +37,7 @@ export default function markdoc(): AstroIntegration {
 						{
 							name: '@astrojs/markdoc',
 							async transform(code, id) {
-								if (!id.endsWith('.mdoc')) return;
+								if (!DEFAULT_MARKDOC_EXTS.some((ext) => id.endsWith(ext))) return;
 								return `import { jsx as h } from 'astro/jsx-runtime';\nimport { Markdoc } from '@astrojs/markdoc';\nimport { Renderer } from '@astrojs/markdoc/components';\nexport const body = ${JSON.stringify(
 									code
 								)};\nexport function getParsed() { return Markdoc.parse(body); }\nexport function getTransformed(inlineConfig) { return Markdoc.transform(getParsed(), inlineConfig) }\nexport async function Content ({ config, components }) { return h(Renderer, { content: getTransformed(config), components }); }\nContent[Symbol.for('astro.needsHeadRendering')] = true;`;
diff --git a/packages/integrations/mdx/src/index.ts b/packages/integrations/mdx/src/index.ts
index 4944db4b8e..2d0b767b98 100644
--- a/packages/integrations/mdx/src/index.ts
+++ b/packages/integrations/mdx/src/index.ts
@@ -35,6 +35,7 @@ export default function mdx(partialMdxOptions: Partial<MdxOptions> = {}): AstroI
 				command,
 			}: any) => {
 				const contentEntryType = {
+					name: 'astro:mdx',
 					extensions: ['.mdx'],
 					async getEntryInfo({ fileUrl, contents }: { fileUrl: URL; contents: string }) {
 						const parsed = parseFrontmatter(contents, fileURLToPath(fileUrl));