The Mülheim/Oberhausen tramway network is a network of tramways forming part of the public transport system focused on Mülheim an der Ruhr and Oberhausen, two cities in the federal state of North Rhine-Westphalia, Germany. Opened in 1897, the network is operated by and Stadtwerke Oberhausen (STOAG), and integrated in the Verkehrsverbund Rhein-Ruhr (VRR).