A liquid dispenser is provided. The liquid dispenser may include a water tank to store water, a cooling module provided in the water tank to circulate cooling water to cool the water to make cold water, a drain valve that connects to the water tank and protrudes from the water tank to discharge the cooling water in the water tank, and a foam insulator that covers an outer circumferential surface of the water tank and contacts the drain valve to prevent the drain valve from being exposed to air.