A vehicle seat comprising a runner made up of a fixed rail fixed to a vehicle floor, and of a moving rail mounted to slide relative to the fixed rail, a front leg having a top end and a bottom end mounted to pivot relative to the vehicle floor, a seat back mounted to pivot relative to the moving rail of the runner, and a seat proper having a front end mounted to pivot on the top end of the front leg. The seat back is mounted to pivot relative to the seat proper, and the seat further comprises at least one locking device adapted to selectively preventing the seat back from pivoting or allowing said seat back to pivot.