Harrow is a large town in Greater London, England, and serves as the principal settlement of the London Borough of Harrow. Lying about 9.5 miles (15.3 km) north-west of Charing Cross and 5.4 miles (8.7 km) south of Watford, the entire town including its localities had a population of 149,246 at the 2011 census, whereas the wider borough had a population of 250,149.