The Epsom Downs Branch is a 3-mile-65-chain (6.1 km) railway line in Greater London and Surrey, England. It runs from Sutton to its southern terminus at Epsom Downs, with intermediate stations at Belmont and Banstead. With the exception of the northernmost 39 ch (780 m), the branch is single track. All stations are managed by Southern, which operates all passenger trains. Most services run between Epsom Downs and London Victoria via Selhurst.

Sutton railway station (sometimes referred to as Sutton (Surrey) on tickets and timetables) is in the London Borough of Sutton in South London and is the main station serving the town of Sutton. It is served by Southern and Thameslink trains, and lies in Travelcard Zone 5, 14 miles 75 chains (14.94 miles, 24.04 km) down the line from London Bridge, measured via Forest Hill.