How do I configure GDM for automatic logins

The GNOME Display Manager (GDM) can be configured to automatically log a user in when it starts up. To do that, you must first configure Pluggable Authentication Module (PAM) support for gdm-autologin. On 5.X and higher, create a /etc/pam.d/gdm-autologin file with the following contents:

auth required pam_nologin.so
auth required pam_permit.so
account required pam_unix.so
session required pam_permit.so


On 4.X, add the following to /etc/pam.conf:

gdm-autologin auth required pam_permit.so
gdm-autologin account required pam_unix.so
gdm-autologin session required pam_permit.so


Once PAM is configured to allow GDM automatic logins, edit /usr/X11R6/etc/gdm/gdm.conf, and set AutomaticLoginEnable=true, and AutomaticLogin equal to the username for which you wish to enable automatic logins. For example:

AutomaticLoginEnable=true
AutomaticLogin=marcus


That will automatically login the user marcus as soon as GDM launches.