Upper Redwater Lake is a narrow freshwater lake in the municipality of Temagami of Northeastern Ontario, Canada, located southeast of the former Rabbit Creek ballast pit along Rabbit Creek Road that comes out at Highway 11. The settlement of Redwater is located on the southeastern shore of Upper Redwater Lake and the Ontario Northland Railway mainline runs along its entire western shore. Its northern end is crossed by the Ontario Northland Railway where the lake sways northeastwards.