A seat sliding device for a vehicle includes a lower rail; an upper rail, which is supported to be able to slide relative to the lower rail and is fixed to a seat; and a bracket, which includes an acting portion to transmit a predetermined external force acting on the upper rail to the lower rail and is fixed to the upper rail, wherein the acting portion is disposed to overlap with the lower rail in an up-down direction which is perpendicular to a longitudinal direction of the sliding device.