Outlook Calendar

Hi @Catherine SH Lee 

If you’re using Classic Outlook for Windows with a Microsoft 365 or Exchange account, whether you can delete a calendar depends on the type of calendar: 

How to delete a calendar 

-Go to Calendar view. 

-In the left Folder Pane, find the calendar. 

-Right‑click the calendar name. 

-Select Delete Calendar. 

-Confirm. 

If the Delete option is greyed out or missing, it means one of these: 

-Primary/default calendar: Cannot be deleted by design. 

-Birthday calendar: You will need to deactivate the Birthday calendar from Outlook Web.  

Go to calendar > Add calendar >Birthdays > Uncheck Turn on birthday calendar. 

-Microsoft 365 Group or Team calendar: Must leave the group instead of deleting in Outlook. 

-Shared calendar: If it reappears after deletion, permissions or auto‑mapping are still in place. Remove it in Outlook on the web or ask the owner/admin to remove your access (especially if Full Access is assigned).

-Internet/subscribed calendars (e.g., holidays): Right-click > Delete Calendar.  

If that doesn’t work, go to File > Account Settings > Account Settings > Internet Calendars > Remove it from the list.  

Sometimes Outlook keeps orphaned calendars, here are some steps you may try: 

1.Check in Outlook on the web (OWA), if you can remove it there, it will sync back 

2.Reset Outlook views: 

-Close classic Outlook completely > press Windows + R > copy and paste the outlook.exe /cleanviews > OK. 
(Please note that this restores default views and removes any custom views you’ve created).

3.Restart Outlook in Safe Mode: 

-Close Outlook completely.       

-Press Win + R, type: outlook.exe /safe > Press Enter.   

 4.Create a new Outlook profile  

Control Panel > Mail > Show Profiles > Add > create a new profile > add your account > set as default > restart Outlook.      

I hope this helps. 

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In classic Outlook for Windows, the way to remove a calendar depends on what kind of calendar it is.

1. Delete a secondary calendar (not the primary one)
   1. Go to Calendar.
   2. In the Folder Pane on the left, right‑click the name of the unwanted calendar.
   3. Select Delete Calendar.
   4. Select Yes to confirm.
   If Delete is grayed out, that calendar cannot be deleted (for example, if it is the primary calendar).
2. Remove shared, team, group, or SharePoint calendars
   1. In Calendar, locate the shared/team/group/SharePoint calendar in the Folder Pane.
   2. Right‑click the calendar.
   3. Select Delete Group or Delete Calendar.
   4. Select Yes to confirm.
   This removes only the copy from Outlook; the source calendar itself remains intact.
3. If the calendar is the primary Outlook calendar The primary calendar cannot be deleted. Instead, either hide/close it or clear its contents: To delete all items from the primary calendar:
   1. In Calendar, select the View tab.
   2. In Current View, select Change View > List.
   3. Click in the item list and press Ctrl+A to select all items.
   4. Right‑click the selection and choose Delete.
   This removes all appointments/events (including automatically added holidays) but leaves the primary calendar itself.

References:

• Delete a calendar in Outlook