The present invention provides a vehicle seat having an active headrest mechanism for moving a headrest forward in a rear collision. The active headrest mechanism has a left-right oriented headrest support section where vertical engagement sections for supporting pillars of the headrest are mounted, and also has an upper link mechanism for moving the headrest support section forward relative to a seatback. The upper link mechanism is installed on a single plate-like upper frame of a seatback frame with a bracket interposed in between.