The Avon River is a river in Perth County, Ontario, Canada. The river was named after the River Avon in England when the town of Stratford was founded on its banks in 1832. The Avon River rises northeast of Stratford and flows southwest, flowing into the North Thames River near St. Marys. It was originally known as the Little Thames River.

Stratford is a city on the Avon River within Perth County in southwestern Ontario, Canada, with a 2021 population of 33,232 in a land area of 30.02 square kilometres (11.59 sq mi). Stratford is the seat of Perth County, which was settled by English, Irish, Scottish and German immigrants, in almost equal numbers, starting in the 1820s but primarily in the 1830s and 1840s. Most became farmers; even today, the area around Stratford is known for mixed farming, dairying and hog production.