Sorry to see you go!
Before deleting your account forever, if you are experiencing issues with your account or with another user, reach out to our support team here: https://support.foursquare.com/hc/en-us/requests/new
To delete your account, please follow these steps:
On a computer,visit foursquare.com/settings.
Click on the “Privacy Settings” tab in the right sidebar.
You'll be taken to a page to confirm the deletion of your account.
Note: There is no way to un-delete an account. This will delete both your Foursquare City Guide and Foursquare Swarm accounts. That means that all of your tips, tastes, and check-ins will be lost. Also, just deleting the app will not delete your account.