A flush toilet includes a bowl having a waste-receiving surface and a rim; on either the left or right side inside the front area of this bowl, a rim water passageway is formed and a rim spouting port is formed; the water passageway formed at the downstream side of this rim spouting port forms a flow path cross section with the inner circumferential surface of the rim, the shelf surface formed under this inner circumferential surface, and the overhang portion formed over the inner circumferential surface; the height dimension of the flow path cross section is set to increase with distance on the downstream side, and the width thereof is set to decrease with distance on the downstream side, so that from the rim spout port toward the downstream side, the cross sectional area of the flow path cross section is approximately constant.