How to remove your StumbleUpon account
Make sure you are logged in, then use the direct below link to delete your account.
Direct removal link: https://www.stumbleupon.com/settings/delete-account
Helpful Trick: Removing online data
Helpful Trick: Remove third-party logins
If you signed up for StumbleUpon using a third-party login such as Facebook or Twitter, you probably want to revoke all access from StumbleUpon. Click here to find out how.