The Thames River is located in southwestern Ontario, Canada.
The Thames flows west 273 kilometers through southwestern Ontario, through the cities of London and Chatham to Lighthouse Cove on Lake St. Clair. It drains 5,825 square kilometres of land.
Called Askunessippi, "the antlered river," by the original Algonquin inhabitants, the river was renamed 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 allow for agriculture. The North and South branches on the upper part of the river flow through valleys created during the retreat of the glaciers during the last ice age. The North and South branches meet at London; the University of Western Ontario is located on the North Branch. From London, the lower part of the river flows through a shallow plain of sand and clay, with an average depth of 23 meters. The lower Thames flows through Delaware, Chatham, Thamesville, as well as Chippewa and Oneida First Nations settlements. Tributaries of the Thames include Dingman Creek, Jeanettes Creek, McGregor Creek, Medway Creek, Pottersburg Creek, Stoney Creek, and Waubuno Creek.
The river was the location of an important battle of the War of 1812. The Battle of the Thames (also known as the Battle of Moraviantown) was fought on October 5, 1813, between American General William Henry Harrison and British General Henry Proctor, along with Procter's ally Tecumseh. Tecumseh was killed in the battle.
On August 14, 2000, the Thames was designated a Canadian Heritage River.