How can I delete my Stack Exchange account(s) and what happens to content I've posted when my account gets deleted?
If your account has interacted with the site by voting or posting, there are two steps:
You can also get to that page via the "contact us" section on the site footer. Please note that account deletion is not instant. It might take several days for your request to be processed.
If your account has never voted or posted a question or answer more than once, you should see a self-delete option on your user page next to the edit link:
Either of these procedures cover deleting your account on one specific site.
Content you've posted on the site is owned by you but licensed to Stack Exchange, and you therefore cannot request that it be deleted with your account.
Also of note, we automatically cull old inactive accounts as documented on the blog: