Esnagi Lake is a large "V"-shaped lake in the Unorganized North part of Algoma District, Ontario, Canada. Part of the Great Lakes Basin, it is about 45 kilometres (28 mi) long and 5.0 kilometres (3.1 mi) wide and lies at an elevation of 344 metres (1,129 ft), with the "V" on its side and the apex facing west. The primary inflows are the Magpie River from Mosambik Lake at the north end of the lake, Tripoli Creek on the west side, and other unnamed creeks. The primary outflow is also the Magpie River, which flows downstream from the south end of the lake at the east switch of the siding at Swanson on the Canadian Pacific Railway transcontinental mainline, and eventually into Lake Superior.