diff --git a/.changeset/loud-trains-take.md b/.changeset/loud-trains-take.md
new file mode 100644
index 0000000000..15a91df49e
--- /dev/null
+++ b/.changeset/loud-trains-take.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': major
+---
+
+**BREAKING**: The default `catalog.orphanStrategy` has been switched to `'delete'`.
diff --git a/plugins/catalog-backend/config.d.ts b/plugins/catalog-backend/config.d.ts
index df7d93006b..2d302b5b33 100644
--- a/plugins/catalog-backend/config.d.ts
+++ b/plugins/catalog-backend/config.d.ts
@@ -160,7 +160,7 @@ export interface Config {
     /**
      * The strategy to use for entities that are orphaned, i.e. no longer have
      * any other entities or providers referencing them. The default value is
-     * "keep".
+     * "delete".
      */
     orphanStrategy?: 'keep' | 'delete';
 
diff --git a/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts b/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts
index a3ef926b47..56b95d901d 100644
--- a/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts
+++ b/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts
@@ -344,7 +344,7 @@ export class DefaultCatalogProcessingEngine {
 
   private startOrphanCleanup(): () => void {
     const orphanStrategy =
-      this.config.getOptionalString('catalog.orphanStrategy') ?? 'keep';
+      this.config.getOptionalString('catalog.orphanStrategy') ?? 'delete';
     if (orphanStrategy !== 'delete') {
       return () => {};
     }