diff --git a/addons/microsoft_calendar/tests/test_create_events.py b/addons/microsoft_calendar/tests/test_create_events.py
index 35edc71da41..a741c788a28 100644
--- a/addons/microsoft_calendar/tests/test_create_events.py
+++ b/addons/microsoft_calendar/tests/test_create_events.py
@@ -474,3 +474,26 @@ class TestCreateEvents(TestCommon):
         # Ensure that event was successfully created in Odoo (no ACL error was triggered blocking creation).
         portal_user_events = self.env['calendar.event'].search([('user_id', '=', portal_user.id)])
         self.assertEqual(len(portal_user_events), 1)
+
+    @patch.object(MicrosoftCalendarService, 'get_events')
+    def test_create_simple_event_from_outlook_without_organizer(self, mock_get_events):
+        """
+        Allow creation of an event without organizer in Outlook and sync it in Odoo.
+        """
+
+        # arrange
+        outlook_event = self.simple_event_from_outlook_attendee
+        outlook_event = dict(self.simple_event_from_outlook_attendee, organizer=None)
+        expected_event = dict(self.expected_odoo_event_from_outlook, user_id=False)
+
+        mock_get_events.return_value = (MicrosoftEvent([outlook_event]), None)
+        existing_records = self.env["calendar.event"].search([])
+
+        # act
+        self.organizer_user.with_user(self.organizer_user).sudo()._sync_microsoft_calendar()
+
+        # assert
+        records = self.env["calendar.event"].search([])
+        new_records = (records - existing_records)
+        self.assertEqual(len(new_records), 1)
+        self.assert_odoo_event(new_records, expected_event)
diff --git a/addons/microsoft_calendar/utils/microsoft_event.py b/addons/microsoft_calendar/utils/microsoft_event.py
index 3f35b3d67f7..1672102156a 100644
--- a/addons/microsoft_calendar/utils/microsoft_event.py
+++ b/addons/microsoft_calendar/utils/microsoft_event.py
@@ -167,6 +167,9 @@ class MicrosoftEvent(abc.Set):
         if self.isOrganizer:
             return env.user.id
 
+        if not self.organizer:
+            return False
+
         organizer_email = self.organizer.get('emailAddress') and email_normalize(self.organizer.get('emailAddress').get('address'))
         if organizer_email:
             # Warning: In Microsoft: 1 email = 1 user; but in Odoo several users might have the same email