Ros Dumhach (anglicized as Rosdoagh and known in English as Rossport) is a Gaeltacht village and townland in northwest County Mayo, Ireland. It is within the barony of Erris and parish of Kilcommon. It lies close to the mouth of Broadhaven Bay on the headland where the confluence of three rivers meet (the Muingnabo, the Glenamoy and the Gweedaney) flowing into Sruth Fada Conn Bay. Its area is 1,446 acres (5.85 km2).