A new fossil genus of decapod Crustacea, belonging to the family Polychelidae is described from James Ross Island, Antarctic Peninsula. The specimen was obtained from a block of reworked Jurassic tuffaceous black shale belonging to the Ameghino (= Nordenskjöld) Formation in the Lower Cretaceous Kotick Point Formation. This is the first report of fossil Polychelidae in the Southern Hemisphere.