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 A3, known as the Portsmouth Road or London Road in sections, is a major road connecting the City of London and Portsmouth passing close to Kingston upon Thames, Guildford, Haslemere and Petersfield. For much of its 67-mile (108 km) length, it is classified as a trunk road and therefore managed by National Highways. Almost all of the road has been built to dual carriageway standards or wider. Apart from bypass sections in London, the road travels in a southwest direction and, after Liss, south-southwest.