Hadleigh (/ˈhædli/) is an ancient market town and civil parish in the Babergh district of Suffolk, England.

; Hædleage, in a late chapter, Thorpe, Diplomat, 527; Headlega, Annals of St Neot, quoted in Plummer's ed.

The manor of Hadleigh, along with those of Lawling in Essex and Monks Eleigh in Suffolk, were among those given to the Priory Church of Canterbury Cathedral.

[7] It has been suggested by Woods (2018) that Wat Tyler and his wife were Hadleigh tenants about 20 years before he was one of the leaders of the 1381 Peasants' Revolt.

Records show a Wat Tyler taking over a freeholding in Coram Street in 1358–59 and it is possible he worked as a tiler.

[6] Hadleigh was one of the East Anglian towns that derived its prosperity from its wool and cloth industries.

It has a 15th-century timber-framed Guildhall and many fine examples of timber and brick listed buildings, some with highly detailed 17th century plasterwork or "pargeting".

In 1252, king Henry III of England granted a weekly market and an annual fair to Gilbert de Kirkeby, his wife Lauretta and their heirs.

By 1438, the Lord of the Manor was William de Clopton, who granted these rights, to fifteen trustees, with an initial annual payment of 6s 8d.

Abutting the Market House to the west was the 'Long Hall newly built' (1438), which appears to have been the home of the Grammar School, the earliest record of which is dated 7 May 1382.

[13] Of these, four are Grade I: the grouping of St Mary's Church, the Deanery Tower, the Guildhall, and the Coffee Tavern in the High Street.

[16] It was restored by Mr and Mrs Baines and given a Noel Turner Award by the Hadleigh Society in 2012.

[17] The Georgian East House, on George Street, is designated a Grade II* listed building.

[18] In March 2013, plans by Babergh District Council to redevelop the site and build houses on the land behind were withdrawn after strong local protest.

[20] In 2018, the building was renovated into two private homes: East House and West Lodge by period property restorers Richard Abel and Ruth McCabe-Abel.

[21] Originating in the 14th century, the Grade II* listed Toppesfield Bridge, over the River Brett, is the oldest in the county still carrying vehicles.

[27] He may have built the original Saxon church at this site, traces of which were revealed in the churchyard to the south of the porch, in 1829 and in 1984.

The deanery, with a tall Tudor gatehouse in brick built just before the Reformation, next to the church, is also a Grade I listed building.

Rowland Taylor, a preacher from the town, and his curate, Richard Yeoman, were martyred by being burned at the stake during the reign of Queen Mary I.

Supermarket Tesco made a number of controversial proposals for the building of a store in the town.

[41] The Lady Lane Industrial estate is the location of Celotex Saint Gobain, the manufacturer of the insulation component in the cladding used at Grenfell Tower.

From 1940 it was the home of Sir Cedric Morris, artist and plantsman, who formed the East Anglian School of Painting and Drawing there.

It operates the cinema ("Hollywood in Hadleigh"), organises luncheon clubs and arranges events.