Reigate (/ˈraɪɡeɪt/ RY-gate) is a town in Surrey, England, around 19 miles (30 km) south of central London. The settlement is recorded in the Domesday Book of 1086 as Cherchefelle, and first appears with its modern name in the 1190s. The earliest archaeological evidence for human activity is from the Paleolithic and Neolithic, and during the Roman period, tile-making took place to the north east of the modern centre.

A motte-and-bailey castle was erected in Reigate in the late 11th or early 12th century. It was originally constructed of timber, but the curtain walls were rebuilt in stone about a century later. An Augustinian priory was founded to the south of the modern town centre in the first half of the 13th century. The priory was closed during the Reformation and was rebuilt as a private residence for William Howard, 1st Baron Howard of Effingham. The castle was abandoned around the same time and fell into disrepair.

During the medieval and early modern periods, Reigate was primarily an agricultural settlement. A weekly market began no later than 1279 and continued until 1895. Key crops included oats, hops and flax, but there is no record of rye being grown in the local area. The economy initially declined in the 18th century, as new turnpike roads allowed cheaper goods made outside the town to become available, undercutting local producers. Following the arrival of the railways in the mid-19th century, Reigate began to expand and the sale of much of the priory estate in 1921 released further land for housebuilding.

Reigate is part of the London commuter belt, and since 1974 it has been one of four towns in the borough of Reigate and Banstead. The borough council is based at the town hall in Castlefield Road, and Surrey County Council has its headquarters at Woodhatch Place. Much of the North Downs, to the north of Reigate, is owned by the National Trust, including Colley Hill, 722 feet (220 m) above ordnance datum (OD) and Reigate Hill 771 feet (235 m) above OD.

In the Domesday Book of 1086, Reigate appears as Cherchefelle and in the 12th century, it is recorded as Crichefeld and Crechesfeld. The name is thought to mean "open space by the hill or barrow".

The name "Reigate" first appears in written sources in the 1190s. Similar forms are also recorded in the late medieval period, including Reigata in 1170, Regate in 1203, Raygate in 1235, Rigate in 1344 and Reighgate in 1604. The name is thought to derive from the Old English rǣge meaning "roe deer" and the Middle English gate, which might indicate an enclosure gate or pass through which deer were hunted. It has also been suggested that the "rei" element may have evolved from the Middle English ray, meaning a marshland or referring to a stream; this theory is considered unlikely as the Old English form of this word is ree rather than rey.

Woodhatch may derive from the Old English word hæc meaning "gate", and the name may mean "gate to the wood". It is possible, in this instance, that the "wood" referred to is the Weald. In 1623, a survey of the manor of Reigate noted a "Bowling Alley lying before the gate of the Tenement called Woodhatch". Alternatively, the name may derive from that of a local resident: A "Thomas ate Chert" is recorded as living at the settlement in the early 14th century, and "Woodhatch" might instead mean "woodland of the ate Chert family".

Reigate is in central Surrey, around 19 mi (30 km) south of central London and 9 mi (14 km) north of Gatwick Airport. The town is in the Vale of Holmesdale, below the North Downs escarpment. The average elevation in the centre is 80 m (260 ft) above ordnance datum (OD) and the area is drained by the Wallace Brook and its tributaries, which feed the River Mole.