Fuel Cell System and Fuel Cell Vehicle Using the Same

An embodiment fuel cell system includes a fuel cell enclosure configured to output electrical energy generated by a fuel cell stack through a stack bus bar, a high-voltage box disposed on the fuel cell enclosure, the high-voltage box including an air inlet port formed at one side thereof, the air inlet port being configured to introduce cold air from outside, and a terminal block assembly including a vent port connected to the fuel cell enclosure, the vent port being configured to deliver the cold air introduced through the air inlet port to the stack bus bar.