diff --git a/.changeset/fresh-lizards-whisper.md b/.changeset/fresh-lizards-whisper.md
new file mode 100644
index 000000000000..aa276c94626c
--- /dev/null
+++ b/.changeset/fresh-lizards-whisper.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Only use Vite config from astro.config.mjs as source of truth
diff --git a/packages/astro/src/core/create-vite.ts b/packages/astro/src/core/create-vite.ts
index 9c728301b258..fd23a27f552a 100644
--- a/packages/astro/src/core/create-vite.ts
+++ b/packages/astro/src/core/create-vite.ts
@@ -100,6 +100,8 @@ export async function createVite(
 
 	// Start with the Vite configuration that Astro core needs
 	const commonConfig: vite.InlineConfig = {
+		// Tell Vite not to combine config from vite.config.js with our provided inline config
+		configFile: false,
 		cacheDir: fileURLToPath(new URL('./node_modules/.vite/', settings.config.root)), // using local caches allows Astro to be used in monorepos, etc.
 		clearScreen: false, // we want to control the output, not Vite
 		logLevel: 'warn', // log warnings and errors only