How do I delete a poll?
To delete a poll that you created, click the green Open button to open the Poll Management Window. Select Details and Actions from the More Poll Options dropdown menu and select Delete.
Only the creator of the poll can delete the poll. However, Owners and Admins of the Slack workspace can delete the message that contains the poll.
Note: If you want to delete a recurring poll, you first need to stop the recurring poll from posting automatically to prevent new ones from being posted.