SEAT ROTATING DEVICE

A seat rotating device capable of achieving both of suppression of floating of a rotating plate from a seat slider and positioning in a front-rear direction of the rotating plate at a seating position is provided. The seat rotating device includes a seat slider including a lower rail and an upper rail, a base plate, a rotating plate including a belt anchor bracket, a coupling unit, a restriction portion, a fixing member, and a load bearing portion. The restriction portion includes an opposed portion opposed, in the front-rear direction, to a rear end of the belt anchor bracket while the rotating plate is located at the seating position and a tab located above the rear end of the belt anchor bracket while the rotating plate is located at the seating position.