Improvement is made in a configuration of a movable portion movable to adjust a length of a seat cushion. A vehicle seat includes a seat cushion having a fixed portion and a movable portion movable relative to the fixed portion for adjustment of a length of the seat cushion, and also includes a notch arranged on the movable portion as a movable portion side engagement portion and an engagement plate piece arranged on the fixed portion as a fixed portion side engagement portion. The engagement plate piece is movable between i) a locking position engaged with the notch to bring the movable portion into an unmovable state, and ii) an unlocking position released from the notch to bring the movable portion into a movable state. The movable portion includes a pressing wire to move the engagement plate piece from the locking position to the unlocking position.