A vehicle seat includes: a seat back which has a backrest support surface for a seat occupant that is variable in shape; a plurality of air bags that are located behind a support surface portion of the seat back and change the shape of the support surface upon introduction or discharge of air thereinto or therefrom; and a control device that is configured to control the introduction and discharge of air into and from the air bags. The control device controls the introduction and discharge of air into and from each air bag based on a state of change in the air in each air bag that occurs when the seat occupant sits on the vehicle seat with the air bags in the set state to change the shape of the backrest support surface to a shape that conforms to the seat occupant's unique sitting position.