The London Borough of Hillingdon is a London borough in Greater London, England. It forms part of outer London and West London, being the westernmost London borough. It was formed in 1965 f…The London Borough of Hillingdon is a London borough in Greater London, England. It forms part of outer London and West London, being the westernmost London borough. It was formed in 1965 from the districts of Hayes and Harlington, Ruislip-Northwood, Uxbridge, and Yiewsley and West Drayton. The borough includes most of Heathrow Airport and Brunel University, and is the second largest of the 32 London boroughs by area.