Wellingborough (/ˈwɛlɪŋbrə/ WEL-ing-brə) is a market town in the North Northamptonshire, Unitary Authority area, England, 65 miles (105 km) from London and 11 miles (18 km) from Northampton, north of the River Nene.

Originally named "Wendelingburgh" (the stronghold of Wændel's people), the Anglo-Saxon settlement is mentioned in the Domesday Book of 1086 as "Wendelburie". The town's market was granted a royal charter in 1201 by King John. At the 2021 census, it had a population of 56,564. The built-up area also includes suburbs Wilby, Great Doddington, Little Irchester, Redhill Grange, Stanton Cross, Waendel View and Glenvale Park.

The town was established in the Anglo-Saxon period and was called "Wendelingburgh", deriving from the Old English waendelburh or waendelingburh meaning 'Waendel's burh' (fortification). It is surrounded by five wells: Redwell, Hemmingwell, Witche's Well, Lady's Well and Whytewell, which appear on its coat of arms. Henrietta Maria, the Queen Consort of King Charles I, came with her physician Théodore de Mayerne to take the waters on 14 July 1627.

The medieval town of Wellingborough housed a modest monastic grange – now the Jacobean Croyland Abbey – which was an offshoot of the monastery of Crowland (or Croyland) Abbey, near Peterborough, some 30 miles (48 km) down-river. This part of the town is known as Croyland.

All Hallows Church is the oldest existing building in Wellingborough and dates from c. 1160. The manor of Wellingborough belonged to Crowland Abbey Lincolnshire, from Saxon times and the monks probably built the original church. The earliest part of the building is the Norman doorway opening in from the later south porch. The church was enlarged with the addition of more side chapels and by the end of the 13th century had assumed more or less its present plan. The west tower, crowned with a graceful broach spire rising to 160 feet (49 m), was completed about 1270, after which the chancel was rebuilt and given the east window twenty years later. The church was restored in 1861 by Edmund Francis Law. The 20th-century Church of St Mary was built by Ninian Comper.

Wellingborough was given a Market Charter dated 3 April 1201 when King John granted it to the "Abbot of Croyland and the monks serving God there" continuing, "they shall have a market at Wendligburg (Wellingborough) for one day each week that is Wednesday".

In the Elizabethan era the Lord of the Manor, Sir Christopher Hatton was a sponsor of Sir Francis Drake's expeditions; Drake renamed one of his ships the Golden Hind after the heraldic symbol of the Hatton family. A hotel in a Grade II listed building built in the 17th century, was known variously as the Hind Hotel and later as the Golden Hind Hotel.

During the English Civil War the largest substantial conflict in the area was the Battle of Naseby in 1645, although a minor skirmish in the town resulted in the killing of a parliamentarian officer Captain John Sawyer. Severe reprisals followed which included the carrying off to Northampton of the parish priest, Thomas Jones, and 40 prisoners by a group of Roundheads. However, after the Civil War Wellingborough was home to a colony of Diggers. Little is known about this period.^{[citation needed]}