A locking device for a vehicle seat, in particular for a motor vehicle seat, is provided with a locking mechanism for the mechanical locking of a movable catch of the locking mechanism with a counter-element, and with an actuator unit for the actuation of the catch via a drive. A hosing is provided in which the locking mechanism is arranged and mounted, with regard to the required installation space. The locking device provides the possibility of the formation of structurally different variants of the locking device. The actuator unit (4) is arranged in the housing as a shared housing (2) together with the locking mechanism (3).