A vehicle seat can include a seat cushion having a main portion and a tiltable portion, and a drive mechanism having a small gear and a large gear. The small and large gears are respectively attached to the main portion while meshing with each other. The tiltable portion is arranged and constructed to vertically move when the large gear is rotated upwardly and downwardly with respect to a rotationally reference position based on rotation of the small gear. The small gear and the large gear are positioned such that rotation centers thereof are vertically offset from each other.