Apple - How to remove Guest option from login screen?

@andyshinn OK, I see on your screen shot, that is not Guest user icon, that is Group user!

It says Other (not Guest).

The Guest user shows with one face, the group shows with multiple faces, like your icon.

I see you are at work. Do you have a group user account set up by your IT people?

Let me clarify that. Someone or something (a program) has put a login and hidden it from you so you can not delete it.

Well you can now do something since you know about it. First lets find out who! then decide if you want to delete it.

I was able to confirm this being tied to "Find My Mac" being enabled by toggling the option while setting up a new Mac, however I'm unable to revert back to the previous state where the only options are normal user accounts. I've disabled "Find My Mac", signed out of iCloud, rebooted, removed com.apple.loginwindow.plist from /Library all with no change.

What I CAN tell you is that you can login without needing to use the trackpad/mouse:

• At the login window you can use the right or left arrow keys to select a user
• Click return to select the user
• Enter your password and click return again to log in