Leatherhead is a town in the Mole Valley district of Surrey, England, about 17 mi (27 km) south of Central London. The settlement grew up beside a ford on the River Mole, from which its name is thought to derive. During the late Anglo-Saxon period, Leatherhead was a royal vill and is first mentioned in the will of Alfred the Great in 880 AD. The first bridge across the Mole may have been constructed in around 1200 and this may have coincided with the expansion of the town and the enlargement of the parish church.

For much of its history, Leatherhead was primarily an agricultural settlement, with a weekly market being held until the mid-Elizabethan era. The construction of turnpike roads in the mid-18th century and the arrival of the railways in the second half of the 19th century attracted newcomers and began to stimulate the local economy. Large-scale manufacturing industries arrived following the end of the First World War and companies with factories in the town included Ronson and Goblin Vacuum Cleaners. Several organisations working with disabled people also opened treatment and training facilities, including The Royal School for the Blind, Queen Elizabeth's Foundation and the Ex-services Welfare Society.

Towards the end of the 20th century, manufacturing in Leatherhead had begun to decline and the town was instead starting to attract service sector employers. The former industrial areas were converted to business parks, which attracted multinational companies, including Esso and Unilever. A controversial redevelopment took place in the town centre in the early 1980s, which included the construction of the Swan Centre. The work, which also included the pedestrianisation of the main shopping area, was widely blamed for a decline in the local retail economy. In 2002, the BBC identified Leatherhead as having one of the worst High Streets in England, but in 2007, the local press described the town centre as "bustling".

The origins and meaning of the name 'Leatherhead' are uncertain. Early spellings include Leodridan (880), Leret (1086), Lereda (1156), Ledreda (1160) and Leddrede (1195).

The name is usually thought to derive from the Old English lēode (people) + rida (a riding path or ford that can be ridden), and thus meaning 'a public ford'. Richard Coates has suggested a derivation from the primitive Welsh lēd-rïd (Brittonic *letorito-) meaning 'grey ford', where the lexical field of lēd (grey) can also extend to brown, but this is not widely accepted.

Leatherhead is a town in central Surrey, around 17 mi (27 km) south of the centre of London. It lies on the southern edge of the London Basin and the highest point in the parish, at Leatherhead Downs, is 135 m (443 ft) above ordnance datum. The High Street runs roughly west to east and was part of the Guildford to Epsom road, which crossed the River Mole at the Town Bridge. The Mole, which passes to the west of the centre, has cut a steep-sided valley through the North Downs, south of the town.

Leatherhead is at the southern edge of the London Basin, where the permeable upper chalk of the North Downs dips beneath the impermeable London Clay. The difference in properties between the two formations results in a high water table and springs are found at regular intervals along the boundary between them. Several settlements were established along this spring line in Anglo-Saxon and early medieval times, including the villages of Ashtead, Fetcham and Effingham, which are linked to Leatherhead by the Guildford to Epsom road.

The earliest evidence of human activity in Leatherhead comes from the Iron Age. Flints, a probable well and two pits were discovered in 2012 during building work on Garlands Road and the finds suggest that the site was also used in the early Roman period. Traces of Iron Age field systems and settlement activity have been observed at Hawks Hill, Fetcham (about 1 km (0.62 mi) southwest of the town centre) and on Mickleham Downs (about 3 km (2 mi) to the south). Also to the south, the Druid's Grove at Norbury Park may have been used for pre-Christian pagan gatherings.