diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a817aa6f4..e6fd2a9d1d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Address issue where we were improperly parsing Grafana feature flags that were enabled via the `feature_flags.enabled`
   method by @joeyorlando ([#2477](https://github.com/grafana/oncall/pull/2477))
 - Fix cuddled list Markdown issue by @vadimkerr ([#2488](https://github.com/grafana/oncall/pull/2488))
+- Fixed schedules slack notifications for deleted organizations ([#2493](https://github.com/grafana/oncall/pull/2493))
 
 ## v1.3.7 (2023-07-06)
 
diff --git a/engine/apps/alerts/tasks/notify_ical_schedule_shift.py b/engine/apps/alerts/tasks/notify_ical_schedule_shift.py
index aff7a4d1d6..af46779ebd 100644
--- a/engine/apps/alerts/tasks/notify_ical_schedule_shift.py
+++ b/engine/apps/alerts/tasks/notify_ical_schedule_shift.py
@@ -186,6 +186,9 @@ def notify_ical_schedule_shift(schedule_pk):
     if schedule.organization.slack_team_identity is None:
         task_logger.info(f"Trying to notify ical schedule shift with no slack team identity {schedule_pk}")
         return
+    elif schedule.organization.deleted_at:
+        task_logger.info(f"Trying to notify ical schedule shift from deleted organization {schedule_pk}")
+        return
 
     MIN_DAYS_TO_LOOKUP_FOR_THE_END_OF_EVENT = 3
 
diff --git a/engine/apps/schedules/tasks/refresh_ical_files.py b/engine/apps/schedules/tasks/refresh_ical_files.py
index 18b7893652..262a3032ec 100644
--- a/engine/apps/schedules/tasks/refresh_ical_files.py
+++ b/engine/apps/schedules/tasks/refresh_ical_files.py
@@ -16,7 +16,7 @@ def start_refresh_ical_files():
 
     task_logger.info("Start refresh ical files")
 
-    schedules = OnCallSchedule.objects.all()
+    schedules = OnCallSchedule.objects.filter(organization__deleted_at__isnull=True)
     for schedule in schedules:
         refresh_ical_file.apply_async((schedule.pk,))
 
@@ -30,7 +30,7 @@ def start_refresh_ical_final_schedules():
 
     task_logger.info("Start refresh ical final schedules")
 
-    schedules = OnCallSchedule.objects.all()
+    schedules = OnCallSchedule.objects.filter(organization__deleted_at__isnull=True)
     for schedule in schedules:
         refresh_ical_final_schedule.apply_async((schedule.pk,))
 
diff --git a/engine/apps/schedules/tests/test_tasks_refresh_ical_files.py b/engine/apps/schedules/tests/test_tasks_refresh_ical_files.py
index 0a7ed738e6..a99fd8e897 100644
--- a/engine/apps/schedules/tests/test_tasks_refresh_ical_files.py
+++ b/engine/apps/schedules/tests/test_tasks_refresh_ical_files.py
@@ -1,9 +1,10 @@
+import datetime
 from unittest.mock import patch
 
 import pytest
 
-from apps.schedules.models import OnCallScheduleICal
-from apps.schedules.tasks.refresh_ical_files import refresh_ical_file
+from apps.schedules.models import OnCallScheduleICal, OnCallScheduleWeb
+from apps.schedules.tasks.refresh_ical_files import refresh_ical_file, start_refresh_ical_files
 
 
 @pytest.mark.django_db
@@ -56,3 +57,25 @@ def test_refresh_ical_file_trigger_run(
 
         assert mock_notify_empty.apply_async.called == run_task
         assert mock_notify_gaps.apply_async.called == run_task
+
+
+@pytest.mark.django_db
+@patch("apps.slack.tasks.start_update_slack_user_group_for_schedules.apply_async")
+def test_refresh_ical_files_filter_orgs(
+    mocked_start_update_slack_user_group_for_schedules,
+    make_organization,
+    make_schedule,
+):
+    organization = make_organization()
+    deleted_organization = make_organization(deleted_at=datetime.datetime.now())
+
+    schedule_from_deleted_org = make_schedule(deleted_organization, schedule_class=OnCallScheduleWeb)
+    schedule = make_schedule(organization, schedule_class=OnCallScheduleWeb)
+
+    with patch("apps.schedules.tasks.refresh_ical_file.apply_async") as mocked_refresh_ical_file:
+        start_refresh_ical_files()
+        assert mocked_refresh_ical_file.called
+        called_args = mocked_refresh_ical_file.call_args_list
+        assert len(called_args) == 1
+        assert schedule.id in called_args[0].args[0]
+        assert schedule_from_deleted_org.id not in called_args[0].args[0]