A device for height adjustment and swivel of a seat for a vehicle has a structure in which a first motor for height adjustment of the seat, a first reduction gear device for increasing output torque of the first motor, and a lifting device configured to lift or lower the seat by being connected to the first reduction gear device are stacked in a vertical direction, and a second motor for driving of seat swivel, a second reduction gear device for increasing output torque of the second motor, a brake device configured to stop the seat are vertically stacked between a bottom of the seat and the first motor, in order to adjust the height of the seat, enable accurate swiveling, and carry out a monopost function of the seat.