Hemel Hempstead is a town in Hertfordshire, England, United Kingdom with a population of 81,143 at the United Kingdom Census 2001 (but now estimated at around 89,000 by Hertfordshire County Council). Developed after World War II as a new town, it has existed as a settlement since the 8th century. It is part of the district (and borough since 1984) of Dacorum and the Hemel Hempstead constituency.

The main railway line between London Euston and the Midlands passes through Apsley and Hemel Hempstead railway stations a mile south of the town centre, as does the Grand Union Canal. These links, as well as the A41 trunk road, follow the course of the Bulbourne river valley. The New Town expansion took place up the valley sides and on to the plateau above the original Old Town. In the 1990s, a motorway-style bypass numbered A41 was built to the south and west of the town across the upland chalk plateau, which does not follow the lie of the land. Hemel Hempstead is also linked to the M1 motorway to the east. The M25 is a few miles to the south. To the north and west lie mixed farm and woodland with scattered villages, part of the Chiltern Hills. To the south lies Watford and the beginnings of the Greater London conurbation. To the east lies St Albans, a historic cathedral and market town and now like Hemel Hempstead, part of the London commuter belt.

Possibly the best view of Hemel Hempstead in its physical setting is from the top of Roughdown Common, a chalk hill to the south of the town

The Jarman Park Leisure centre was opened, containing eight film screens run by Empire Cinemas (previously Odeon Cinemas), ten pin bowling (Hotshots), an ice rink (Silver Blades), a water park (Aqua Splash) and night clubs (Lava and Ignite). This development, and those of the adjacent McDonalds restaurant and Tesco superstore, were built on land originally donated to the town for recreational purposes. Land has also been reserved for a hotel, but to date (October 2007) this remains derelict. Replacement openspace was created to the east of the town, near Leverstock Green, Longdean Park and Nash Mills.

The former Dickinsons factory site, straddling the canal at Apsley, has been redeveloped with housing, a mooring basin, and an hotel. An office block is planned. Some buildings have been retained for their historic interest and to provide a home for the projected Paper Museum.

An indoor shopping mall was developed adjacent to the south end of the Marlowes retail area, and in 2005 the Riverside development designed by Bernard Engle Architects was opened, effectively extending the main shopping precinct towards the Plough roundabout. The new centre includes several outlets for national retailers including Debenhams, Starbucks, HMV, Waterstones, and more. These two developments have moved the "centre of gravity" of the retail centre away from the traditional market and the north end of Marlowes has become an area for secondary outlets.

Further extensive redevelopment of the northern end of Marlowes has recently (October 2007) been given the green light and is scheduled to be complete by 2013.