London Borough of Hillingdon | 16,900 followers on LinkedIn. Putting our residents first. | In Hillingdon, putting our residents first is at the heart of everything we do - it's the reason that we come to work every day. We know that our employees make a valuable contribution to the services we deliver to more than 300,000 residents. Located 14 miles west of Central London and with Heathrow Airport in its boundaries, Hillingdon is the second largest borough in London.