Horton Kirby and South Darenth, formerly just Horton Kirby is a civil parish in the Sevenoaks district of Kent, England. The parish is located in the River Darent valley between Sevenoaks town and Dartford: it consists of the two villages of Horton Kirby and South Darenth. On 1 April 1979 the parish was renamed from "Horton Kirby" to "Horton Kirby& South Darenth". Horton Kirby Paper Mills in South Darenth were founded by Henry Hall at the beginning of the 19th century.