A retractable seat of laterally folding type wherein a seat portion thereof is caused by a motor to displace in a direction laterally of a vehicle. The seat portion is pivotally connected, via connecting arm and support elements, with a support base element provided in the vehicle body. The motor and drive transmission elements are securely provided in the seat portion, such that the motor is operatively connected via the drive transmission element with a drive shaft fixed to one end of the connecting arm. Operation of the motor causes displacement of the seat portion in the direction laterally of the vehicle body toward one of a use position on a floor and a non-use storage position where the seat portion extends upright adjacent to a lateral side of the vehicle. The motor is controlled by electric and electronic elements and systems.