Waterlooville is a town in the Borough of Havant in Hampshire, England, approximately 6 miles (9.7 km) north northeast of Portsmouth. It is the largest town in the borough. The town had a population of 64,350 in the 2011 Census. It is surrounded by Purbrook, Blendworth, Cowplain, Lovedean, Clanfield, Catherington, Crookhorn, Denmead, Hambledon, Horndean and Widley. It forms part of the South Hampshire conurbation. The town formed around the old A3 London to Portsmouth road.

The Borough of Havant is a local government district with borough status in Hampshire, England. Its council is based in Havant. Other towns and villages within the borough include Bedhampton, Cowplain, Emsworth, Hayling Island, Purbrook, Waterlooville and Widley. The borough covers much of the semi-urban area in the south east of Hampshire, between the city of Portsmouth and the West Sussex border.