Actually Outlook does not support to change meeting organizer or owner except creating a new one.

How to cancel outlook meeting when you are not the organizer. If you want to cancel one or all meetings that are part of a recurring series see Cancel all future meetings in a series. Right-click the meeting in your calendar and select Delete. After declining a meeting invitation the email will be moved to the Deleted Items folder please open the Deleted Items folder and find the declined meeting invitation email.

Give an account full mailbox permissions and open the meeting via outlook to cancel the meeting which you can refer to the link. If a user sends a meeting request to an outside user with RTF content or attachment it seems that Exchange will convert the meeting request to HTML and attach an ICS file as the meeting request. The meeting form will change into a meeting cancellation form.

To cancel a meeting in outlook you have to send a cancellation message using outlook. If you are not the meeting organizer the only way to remove future occurrences without removing past occurrences is to delete each instance of a recurring meeting individually. Type a message to let the attendees know the meeting is cancelled.

However the meeting can be cancelled by a third party. Right-click on the meeting then click Cancel Meeting If you havent invited anyone or youre not the organizer select Delete or Delete Meeting instead. Find the meeting on the calendar and double-click the meeting.

Search for the site that contains the calendar event and go to that site. Go to the O365 admin portal. Sign in to vote.

Double-click the meeting to open it. In the meeting invitation go to the Meeting tab and select Cancel Meeting. Switch to your Calendar and find the meeting.