A vehicle fuel cooling device includes a return passage and a fuel cooling unit arranged on the return passage. A non-injected surplus fuel of a fuel supplied to a fuel injection valve is returned to a fuel tank through the return passage as a return fuel. When a part of the cooling medium of a vehicle air conditioning system is circulated to the fuel cooling unit, the cooling medium flowing through the fuel cooling unit cools the return fuel through heat exchange. In the vehicle fuel cooling device, when a part of the cooling medium is circulated to the fuel cooling unit to cool the return fuel, an amount of return fuel to be returned to the fuel tank is increased compared to when the return fuel is not cooled.