Fort Severn (SEH-vuhrn), village, NW Ont., Canada, on Hudson Bay, at mouth of Severn R.; 55°59'N 87°36'W. Trading post. Built by the British (1685), it was burned (1689) to prevent capture by the French. Fr. fort (1691) changed hands repeatedly, until handed over to Hudsons Bay Company under Treaty of Utrecht (1713).