diff --git a/.changeset/pink-buttons-destroy.md b/.changeset/pink-buttons-destroy.md
new file mode 100644
index 000000000..f5291b456
--- /dev/null
+++ b/.changeset/pink-buttons-destroy.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Only show the buildOptions.site notice if not already set
diff --git a/packages/astro/src/build.ts b/packages/astro/src/build.ts
index 073dbd2c3..c5aac23c7 100644
--- a/packages/astro/src/build.ts
+++ b/packages/astro/src/build.ts
@@ -53,7 +53,9 @@ export async function build(astroConfig: AstroConfig, logging: LogOptions = defa
   };
 
   // warn users if missing config item in build that may result in broken SEO (can’t disable, as they should provide this)
-  warn(logging, 'config', `Set "buildOptions.site" to generate correct canonical URLs and sitemap`);
+  if (!astroConfig.buildOptions.site) {
+    warn(logging, 'config', `Set "buildOptions.site" to generate correct canonical URLs and sitemap`);
+  }
 
   const mode: RuntimeMode = 'production';
   const runtime = await createRuntime(astroConfig, { mode, logging: runtimeLogging });