Abstract: A system for humidification of a fuel cell electric vehicle includes a fuel cell stack for producing electrical energy through an electrochemical reaction of hydrogen and oxygen, a water supply tank for storing water generated during power generation in the fuel cell stack, a first duct for supplying air exhausted from a heating, ventilation, and air conditioning (HVAC) apparatus to a vehicle glass, a second duct for supplying air exhausted from the HVAC apparatus into the vehicle interior, a humidification apparatus for humidifying air supplied through the second duct using water supplied from the water supply tank, and a controller that supplies air to the vehicle glass through the first duct to perform anti-fogging control of the vehicle glass when adjusting an inside humidity of the vehicle using the humidification apparatus.