Thames River, Ontario

Thames River
North Thames River, just upstream from the confluence with the Avon River near Stratford, Ontario
Name origin: after the River Thames in England
Country	Canada
Province	Ontario
Region	Southwestern Ontario
Part of	Great Lakes Basin
Source
- location	Near
Mouth	Lake Saint Clair
- location	Lighthouse Cove
- elevation	173 m (568 ft)
- coordinates	42°19′9″N 82°27′15″W / 42.31917°N 82.45417°W / 42.31917; -82.45417Coordinates: 42°19′9″N 82°27′15″W / 42.31917°N 82.45417°W / 42.31917; -82.45417
Length	273 km (170 mi)
Basin	5,825 km2 (2,249 sq mi)
Discharge	for Chatham
- average	52.9 m3/s (1,868 cu ft/s)
- max	1,090 m3/s (38,493 cu ft/s)
- min	8.25 m3/s (291 cu ft/s)
Location of the mouth of the Thames River in southern Ontario

The Thames River is located in southwestern Ontario, Canada.

The Thames flows west 273 kilometres (170 mi) through southwestern Ontario, through the cities of , London and Chatham to Lighthouse Cove on Lake St. Clair. Its drainage basin is 5,825 square kilometres (2,249 sq mi).

Called Askunessippi (Anishinaabe language: Eshkani-ziibi, "the antlered river") by the Odawa and Ojibwa inhabitants, who together with the Neutrals have lived in the area since before Europeans arrived, the river was named after the River Thames in England by Lieutenant Governor John Graves Simcoe in 1793.

Much of the Thames is surrounded by deciduous Carolinian forests, although much of this forest has been removed to permit agriculture and other forms of development. Three separate dams are used to control seasonal flooding in the watershed: Wildwood Dam, and the Fanshawe Dam.

There are three rivers in the watershed with Thames in the name — the Thames River itself, North Thames River, and Middle Thames River. These are also known locally as South Branch, North Branch, and Middle Branch. The South Branch is the main stem Thames River and officially carries the Thames River name.