Downton is a village and civil parish on the River Avon in southern Wiltshire, England, about 6 miles (10 km) southeast of the city of Salisbury. The parish is on the county boundary with Hampshire and is close to the New Forest; it includes the villages of Wick and Charlton-All-Saints, and the small ancient settlement of Witherington. The Trafalgar Park estate erased the former settlement of Standlynch. The parish church, Trafalgar House, and two more houses are Grade I listed.

The River Avon is in the south of England, rising in Wiltshire, flowing through that county's city of Salisbury and then west Hampshire, before reaching the English Channel through Christchurch Harbour in the Bournemouth, Christchurch and Poole conurbation of Dorset.