A leak proof drinking cup including a valve assembly and a removable lid with a drinking spout and a vent is disclosed. The valve assembly includes a drinking valve, a venting valve, or both. When in use, the valve assembly engages with the lid to prevent leaks or spills and to permit the flow of air into the cup. When not in use, the valve assembly disengages from the lid and the valve is open to facilitate proper cleaning of the valve assembly.