A flush toilet includes a toilet main body and a tank device. The tank device includes a storage tank, and a water supply unit configured to supply flush water to the storage tank. The storage tank includes a first upper surface including a water passage port through which the flush water supplied from the water supply unit flows into the storage tank, a second upper surface that is lower than the first upper surface, and a third upper surface that is provided between the first upper surface and the second upper surface and that is lower than the second upper surface. The storage tank further includes an air vent unit that is provided at the second upper surface and that is configured to purge air from the storage tank.