Provided is a vehicle seat which is attached to a floor of a vehicle via a rail device and a coupling device with a high level of stiffness so as to minimize deformation of the rail device and the coupling device without substantially increasing the weight and the manufacturing cost of the seat. The vehicle seat is provided with an upper engagement portion secured to a member on a side of an upper rail of the rail device, and a lower engagement portion secured to a member on a side of a lower rail of the rail device and including a part opposing a corresponding part of the upper engagement portion from above defining a prescribed gap therebetween. The coupling device is provided laterally spaced from the rail device, and the upper engagement portion and the lower engagement portion are provided substantially directly above the coupling device.