Purley is an area of the London Borough of Croydon in London, England, 11.7 miles (18.8 km) south of Charing Cross, with a history going back at least 800 years. It was originally granted as an estate from holdings at Sanderstead and until as a district of Surrey and then, with neighbouring Coulsdon, as an urban district that became an electoral ward of the London Borough of Croydon, becoming part of the ceremonial county of London, in 1965. In 2018 the Purley ward was divided into two: Purley and Woodcote, and Purley Oaks and Riddlesdown.

The London Borough of Croydon is a London borough in south London, part of Outer London. It covers an area of 87 km2 (33.6 sq mi). It is the southernmost borough of London. At its centre is the historic town of Croydon from which the borough takes its name; while other urban centres include Coulsdon, Purley, South Norwood, Norbury, New Addington, Selsdon and Thornton Heath. Croydon is mentioned in Domesday Book, and from a small market town has expanded into one of the most populous areas on the fringe of London. The borough is now one of London's leading business, financial and cultural centres, and its influence in entertainment and the arts contribute to its status as a major metropolitan centre. Its population is 390,719, making it the largest London borough and sixteenth largest English district.