Avon was settled in 1645 and was originally a part of Farmington but was sold to the Puritans in a land charter granted by the Duke of York in 1830. Avon was originally called Northington (the north parish) before it broke off from Farmington. According to the Avon Historical Society, Avon's independence was rooted in the need for a church that was more accessible to the growing town's population than the Congregational Church in Farmington. The town eventually commissioned someone to come north from the Yale Divinity School to found the first church.
Avon Probate Court covers Town of Avon. Constituted May session 1884, from Farmington.