diff --git a/.changeset/twenty-llamas-type.md b/.changeset/twenty-llamas-type.md
new file mode 100644
index 000000000..34b74888d
--- /dev/null
+++ b/.changeset/twenty-llamas-type.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Respect `vite.envPrefix` if provided
diff --git a/packages/astro/src/core/build/static-build.ts b/packages/astro/src/core/build/static-build.ts
index deb8a0b05..561b24372 100644
--- a/packages/astro/src/core/build/static-build.ts
+++ b/packages/astro/src/core/build/static-build.ts
@@ -161,7 +161,7 @@ async function ssrBuild(opts: StaticBuildOptions, internals: BuildInternals, inp
 			// SSR needs to be last
 			ssr && vitePluginSSR(internals, settings.adapter!),
 		],
-		envPrefix: 'PUBLIC_',
+		envPrefix: viteConfig.envPrefix ?? 'PUBLIC_',
 		base: settings.config.base,
 	};
 
@@ -230,7 +230,7 @@ async function clientBuild(
 			}),
 			...(viteConfig.plugins || []),
 		],
-		envPrefix: 'PUBLIC_',
+		envPrefix: viteConfig.envPrefix ?? 'PUBLIC_',
 		base: settings.config.base,
 	};
 
diff --git a/packages/astro/src/core/create-vite.ts b/packages/astro/src/core/create-vite.ts
index 06c2e8bb0..7f3c18824 100644
--- a/packages/astro/src/core/create-vite.ts
+++ b/packages/astro/src/core/create-vite.ts
@@ -110,7 +110,7 @@ export async function createVite(
 		],
 		publicDir: fileURLToPath(settings.config.publicDir),
 		root: fileURLToPath(settings.config.root),
-		envPrefix: 'PUBLIC_',
+		envPrefix: settings.config.vite?.envPrefix ?? 'PUBLIC_',
 		define: {
 			'import.meta.env.SITE': settings.config.site
 				? JSON.stringify(settings.config.site)