A seat apparatus for a vehicle includes a first bracket having an upper end and a lower end pivoted to a floor of the vehicle, a second bracket located behind the first bracket along the vehicle lengthwise direction and having an upper end and a lower end pivoted to the floor of the vehicle, a seat-cushion having a front end pivoted to the upper end of the first bracket and a rear end connected to the upper end of the second bracket so as to be movable relative thereto, a seat-back having a lower end connected fixedly to the upper end of the second bracket and making a reclining angle relative to the seat-cushion, a locking mechanism having a locking condition in which the reclining angle is held and an unlocking position in which the seat-back is rotatable relative to the seat-cushion, and an operating device for establishing the unlocking condition of the locking mechanism in concurrence with a rotation of the seat-back toward the seat-cushion in a vehicle frontward direction movement.