The Common Wadden Sea Secretariat (CWSS) in Wilhelmshaven, Germany, is the Secretariat to the Trilateral Wadden Sea Cooperation (the Danish, Dutch, German cooperation at government level for the protection of the Wadden Sea) and the coordinating hub for the Wadden Sea World Heritage. The Secretariat is located in Wilhelmshaven, Germany.
The working language of the Trilateral Wadden Sea Cooperation and CWSS is English.