Waterlooville is a market 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 has a population of about 64,350 and 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.
Waterlooville is twinned with Maurepas, Yvelines in France and Henstedt-Ulzburg in Germany.