Burgess Hill is a town and civil parish in West Sussex, England, close to the border with East Sussex, on the edge of the South Downs National Park, 39 mi south of London, 10 mi north of Brighton and Hove, and 29 mi northeast of the county town, Chichester. It had an area of 3.7 sq mi and a population of 30,635 at the 2011 Census, making it the fourth most populous parish in the county and the most populous in the Mid Sussex District.