A folding seat actuator may include a wire configured to be coupled to a seat back or a seat cushion, a coiling gear connected to the wire configured to fold a seat by winding the wire around the coiling gear when the coiling gear is rotated, a reduction gear interlocked with the coiling gear to rotate the coiling gear, a power source for providing rotational force to the reduction gear, and an elastic body for providing rotational force to the reduction gear such that the reduction gear is restored to a set position after rotating by the power source.