A vehicle seat comprising a seat cushion having a seat cushion main body portion and seat cushion side portions that are disposed on both sides in a seat width direction of the seat cushion main body portion; a seat back having a seat back main body portion and seat back side portions that are disposed on both sides in the seat width direction of the seat back main body portion; and a varying mechanism supporting at least one of the seat cushion main body portion and the seat back main body portion, and varying the position of the seat cushion main body portion in a seat upward and downward direction relative to the seat cushion side portions, and/or varying the position of the seat back main body portion in a seat frontward and rearward direction relative to the seat back side portions.