diff --git a/src/Plugin.php b/src/Plugin.php
index 1894ce421d..eacc59985a 100755
--- a/src/Plugin.php
+++ b/src/Plugin.php
@@ -254,7 +254,7 @@ public static function editions(): array
     /**
      * @inheritDoc
      */
-    public string $schemaVersion = '5.1.0.2';
+    public string $schemaVersion = '5.1.0.3';
 
     /**
      * @inheritdoc
diff --git a/src/elements/Variant.php b/src/elements/Variant.php
index e84c2a6593..9758491a38 100755
--- a/src/elements/Variant.php
+++ b/src/elements/Variant.php
@@ -888,6 +888,20 @@ public static function gqlScopesByContext(mixed $context): array
         return ['productTypes.' . $context->uid];
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function getSupportedSites(): array
+    {
+        $owner = $this->getOwner();
+
+        if (!$owner) {
+            return [Craft::$app->getSites()->getPrimarySite()->id];
+        }
+
+        return $this->getOwner()->getSupportedSites();
+    }
+
     /**
      * @inheritdoc
      * @throws Exception
diff --git a/src/migrations/m240923_132625_remove_orphaned_variants_sites.php b/src/migrations/m240923_132625_remove_orphaned_variants_sites.php
new file mode 100644
index 0000000000..ce7bac534d
--- /dev/null
+++ b/src/migrations/m240923_132625_remove_orphaned_variants_sites.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace craft\commerce\migrations;
+
+use craft\db\Migration;
+use craft\db\Query;
+
+/**
+ * m240923_132625_remove_orphaned_variants_sites migration.
+ */
+class m240923_132625_remove_orphaned_variants_sites extends Migration
+{
+    /**
+     * @inheritdoc
+     */
+    public function safeUp(): bool
+    {
+        // Find all existing combinations of product and site IDs
+        $allProductsSites = (new Query())
+            ->select(['elementId', 'siteId'])
+            ->from('{{%elements_sites}}' . ' es')
+            ->innerJoin('{{%commerce_products}}' . ' p', '[[es.elementId]] = [[p.id]]')
+            ->collect();
+
+        // Group them by product ID
+        $siteIdsByProductId = $allProductsSites->groupBy('elementId')->map(function($row) {
+            return collect($row)->pluck('siteId')->toArray();
+        }
+        );
+
+        // Find all existing combinations of variant and site IDs
+        $allVariantsSites = (new Query())
+            ->select(['es.id', 'elementId', 'siteId', 'primaryOwnerId'])
+            ->from('{{%elements_sites}}' . ' es')
+            ->innerJoin('{{%commerce_variants}}' . ' v', '[[es.elementId]] = [[v.id]]')
+            ->collect();
+
+        // Find all variants that are not associated with any of their product's sites
+        $orphanedVariantsSites = array_values($allVariantsSites->filter(function($row) use ($siteIdsByProductId) {
+            return !in_array($row['siteId'], $siteIdsByProductId[$row['primaryOwnerId']]);
+        })->map(fn($row) => $row['id'])->toArray());
+
+        if (empty($orphanedVariantsSites)) {
+            return true;
+        }
+
+        // Bulk delete the orphaned variants' site rows (if any) 1000 at a time
+        foreach (array_chunk($orphanedVariantsSites, 1000) as $chunk) {
+            $this->delete('{{%elements_sites}}', ['id' => $chunk]);
+        }
+
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function safeDown(): bool
+    {
+        echo "m240923_132625_remove_orphaned_variants_sites cannot be reverted.\n";
+        return false;
+    }
+}