Harrow () is a large suburban town in Greater London, England. It serves as the principal settlement of the London Borough of Harrow, lying about 10.5 miles (16.9 km) northwest of Charing Cross, and 5.4 miles (8.7 km) south of Watford. The entire town, including its localities Harrow on the Hill, Harrow Weald, Headstone, North Harrow, Kenton, Rayners Lane, South Harrow, Wealdstone and West Harrow, had a population of 149,246 as of the 2011 census, whereas the wider borough had a population of 250,149.