Sydenham River (Lake Huron)
Not to be confused with Sydenham River (Lake Saint Clair).
The Sydenham River is a river in Grey County in southern Ontario. The river flows north from a source near Williamsford, drops over the Niagara Escarpment at Inglis Falls and empties into Owen Sound harbour on Georgian Bay. It was named after Lord Sydenham, governor of Canada from 1839 to 1841.
The Spey River is a tributary of this river.