Charlwood is a village and civil parish in the Mole Valley district of Surrey, England. It is immediately north-west of London Gatwick Airport in West Sussex, close west of Horley and north of Crawley. The historic county boundary between Surrey and Sussex ran to the south of Gatwick Airport. Boundaries were reformed in 1974 with the county boundary between Surrey and West Sussex, delineated by the Sussex Border Path, runninh along the northern perimeter of the airport, and the southern extent of Charlwood.