diff --git a/src/sentry/features/temporary.py b/src/sentry/features/temporary.py
index bce608914410..5b941ee53b17 100644
--- a/src/sentry/features/temporary.py
+++ b/src/sentry/features/temporary.py
@@ -304,6 +304,8 @@ def register_temporary_features(manager: FeatureManager) -> None:
     manager.add("organizations:issue-activity-feed-v2", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     # Enable new stack trace component for issue details
     manager.add("organizations:issue-details-new-stack-trace", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
+    # Enable invalidating group derived data when groups are merged
+    manager.add("organizations:hard-delete-derived-data-invalidation", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable double-reading from EAP for issue feed search queries
     manager.add("organizations:issue-feed.eap-search", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Remove trace and breadcrumbs from issue summary input
diff --git a/src/sentry/tasks/merge.py b/src/sentry/tasks/merge.py
index cee271251bc1..d79fd1e5b2a4 100644
--- a/src/sentry/tasks/merge.py
+++ b/src/sentry/tasks/merge.py
@@ -8,8 +8,9 @@
 from django.db.models.functions import Coalesce
 from taskbroker_client.retry import Retry
 
-from sentry import eventstream, similarity, tsdb
+from sentry import eventstream, features, similarity, tsdb
 from sentry.db.models.base import Model
+from sentry.issues.derived.processing import invalidate_group_derived_data
 from sentry.issues.models.groupactionlogentry import GroupActionLogEntry
 from sentry.models.group import Group
 from sentry.silo.base import SiloMode
@@ -59,7 +60,10 @@ def merge_groups(
     from_object_id = from_object_ids[0]
 
     try:
-        new_group, _ = get_group_with_redirect(to_object_id)
+        new_group, _ = get_group_with_redirect(
+            to_object_id,
+            queryset=Group.objects.select_related("project__organization"),
+        )
     except Group.DoesNotExist:
         logger.warning(
             "group.malformed.invalid_id",
@@ -206,9 +210,17 @@ def merge_groups(
             recursed=True,
             eventstream_state=eventstream_state,
         )
-    elif eventstream_state:
-        # All `from_object_ids` have been merged!
-        eventstream.backend.end_merge(eventstream_state)
+    else:
+        if features.has(
+            "organizations:hard-delete-derived-data-invalidation",
+            new_group.project.organization,
+        ):
+            # hard delete derived data on the new group - it will be rebuilt when the next action is processed
+            invalidate_group_derived_data(new_group.id)
+
+        if eventstream_state:
+            # All `from_object_ids` have been merged!
+            eventstream.backend.end_merge(eventstream_state)
 
     return True
 
diff --git a/tests/sentry/tasks/test_merge.py b/tests/sentry/tasks/test_merge.py
index 4a19075844a3..62412d183c21 100644
--- a/tests/sentry/tasks/test_merge.py
+++ b/tests/sentry/tasks/test_merge.py
@@ -2,6 +2,7 @@
 from unittest.mock import patch
 
 from sentry import buffer, eventstream
+from sentry.issues.models.groupderiveddata import GroupDerivedData
 from sentry.models.group import Group
 from sentry.models.groupenvironment import GroupEnvironment
 from sentry.models.groupmeta import GroupMeta
@@ -13,6 +14,7 @@
 from sentry.tasks.post_process import fetch_buffered_group_stats
 from sentry.testutils.cases import SnubaTestCase, TestCase
 from sentry.testutils.helpers.datetime import before_now
+from sentry.testutils.helpers.features import with_feature
 from sentry.testutils.helpers.redis import mock_redis_buffer
 from sentry.utils import redis
 
@@ -222,6 +224,20 @@ def test_merge_includes_pending_buffer_increments(self) -> None:
         assert new_group.times_seen_pending == 3
         assert new_group.times_seen_with_pending == 168
 
+    @with_feature("organizations:hard-delete-derived-data-invalidation")
+    def test_merge_invalidates_derived_data(self) -> None:
+        project = self.create_project()
+        old_group = self.create_group(project)
+        new_group = self.create_group(project)
+
+        GroupDerivedData.objects.create(group=new_group)
+
+        with self.tasks():
+            merge_groups([old_group.id], new_group.id)
+
+        assert Group.objects.filter(id=old_group.id).exists() is False
+        assert GroupDerivedData.objects.filter(group_id=new_group.id).exists() is False
+
     @mock_redis_buffer()
     def test_merge_original_group_id(self) -> None:
         project = self.create_project()