Cancel a recurring meeting series in Outlook

In classic Outlook, on the navigation bar, select  Calendar.

On the calendar grid, select an instance of the meeting you want to cancel.

On the ribbon, select Cancel Meeting > Cancel Series.

Type a message to let the attendees know the future meetings are cancelled, then select Send Cancellation. 

In new Outlook​​​​​​​, open your calendar and double-click on any meeting in the series.

Below the toolbar, select Edit series.

Below the end date, select the text that describes the recurrence pattern ("Occurs every ...").

In the Repeat dialog, select the end date, and change it to a date prior to the next meeting in the series. Then select Save. 

Click Send to save the changes and notify the attendees.