A fuel cell system includes a fuel cell, a supercharger, a coolant circuit, a pump controller, and a pressure regulating mechanism. The supercharger applies pressure to cathode gas and supplies the cathode gas to the fuel cell. The coolant circuit has a coolant circulation pump and a cooler and circulates a coolant to be supplied to a coolant channel in the fuel cell. The pressure regulating mechanism regulates coolant pressure in the fuel cell. The pump controller controls a rotation speed of the pump in accordance with a heat release amount required by the fuel cell and controls the pump in a range lower than or equal to an upper limit for the rotation speed set based on one or both of inlet coolant pressure of the pump or a correlation value thereof and an inlet coolant temperature of the pump or a correlation value thereof.