There are several rivers named Black River in the province of Ontario, Canada.

The Black River in Hastings County, Ontario joins the Moira River near Tweed, Ontario.

The Black River in York Regional Municipality, Ontario originates in the Oak Ridges Moraine and flows north to empty into Lake Simcoe. Agriculture is the most important use of the land in this river's watershed.

The Black River in Simcoe County, Ontario flows south and west from the Muskoka Region south of the Lake of Bays to empties into Lake Couchiching. This river is used for recreational canoeing and kayaking. The Head River is a tributary of this river.

The Black River in Cochrane District, Ontario is a tributary of the Abitibi River.

The Black River in Thunder Bay District, Ontario flows from headwaters near Manitouwadge, Ontario to empty into Lake Superior south of the town of Marathon, Ontario.

See also

• List of Ontario rivers