A fuel cell vehicle mounted with a fuel gas tank in an underfloor of the vehicle. The fuel cell vehicle includes: a floor that has a projecting portion projecting upward in a height direction of the vehicle and extending along a front and rear direction of the vehicle; a fuel gas tank arranged under the projecting portion in the height direction of the vehicle and fixed to the floor; and an undercover arranged under the fuel gas tank in the height direction of the vehicle. The undercover has a fixation protruded portion that projects upward in the height direction of the vehicle in a side of the fuel gas tank in a width direction of the vehicle, and being fixed to the floor by the fixation protruded portion.