Uxbridge is a suburban town in west London, England, and the administrative headquarters of the London Borough of Hillingdon, 15.4 miles (24.8 km) northwest of Charing Cross. Uxbridge formed part of the parish of Hillingdon in the county of Middlesex. As part of the suburban growth of London in the 20th century it expanded and increased in population, becoming a municipal borough in 1955, and part of Greater London in 1965.