Delete a calendar
When you delete a calendar from your Calendars list, all events associated with the calendar are also deleted.
You can’t delete all of the calendars in the list because it must always contain at least one calendar.
WARNING: Any calendar deletions you make occur on every device that has the iCloud Calendar feature turned on. For example, if your iPhone and Mac have iCloud Calendar turned on and you delete a calendar in the iCloud Calendar web app, the calendar is also deleted in the Calendar app on your iPhone and Mac.
Delete a calendar
Click Edit below the sidebar.
Click the Delete button to the right of the calendar’s name, then click Delete.
See also