It’s not commended to enable and login as root user in Ubuntu Linux. sudo command can do most works if you need super user privilege. But if you do need or have a good reason to login Ubuntu as root, here’s a way to login root via LightDM. Do it at your own risk!

Since Ubuntu 11.10, the default display manager was changed to LightDM. It’s no longer supported to login with an arbitrary username. You can use GDM to login as root but it takes time installing packages and some don’t really want to replace LightDM.

Enable Root Login via LightDM:

First of all, enable root user by giving a password. In terminal execute:

sudo passwd root

enter current user password and then input a root password twice.

Then, edit the /etc/lightdm/lightdm.conf by your favorite editor and add this line:


Now, reboot! In login screen, there’s a more option “Login” which promts to input Username and Password. You know what to do next ^_^.