Harefield is a village in the London Borough of Hillingdon, England, 17 miles northwest of Charing Cross near Greater London's boundary with Buckinghamshire to the west and Hertfordshire to the north. The population at the 2011 Census was 7,399. Harefield is the westernmost settlement in Greater London, and lies outside the capital's contiguous built-up area. Harefield is near Denham, Ickenham, Northwood, Rickmansworth, Ruislip and Uxbridge.