Fornham St Martin is a village and civil parish in the St Edmundsbury.

Located on the northern outskirts of Bury St Edmunds off east and west from the A134, in 2005 its population was 1300.

Its parish council is shared with neighbouring Fornham St Genevieve, and is known as Fornham St Martin cum St Genevieve Parish Council.

Near the current Lark Valley Drive, a smock windmill used to stand. It collapsed in 1927.

The village has one public house, the Woolpack, but no shops. Its school closed in the early 1950s.

The name "Fornham" is thought to be Saxon meaning "The homestead by the trout stream" and the village is well documented in the Domesday Book.

The Battle of Fornham, one of the most significant battles in English history took place in Fornham Park and the surrounding area in 1173. Scribes of the time variously estimated that between 3,000 and 10,000 Flemish mercenaries were slaughtered and lie beneath the fields, woodland and ditches.

Fornham once had a reputation for "pie-ladies" – women who walked to the abbey in Bury St Edmunds to feed the monks.

The village appears on John Speed's 1610 map as "Fernham mertin" and in 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described the town as a parish in Thingoe district, Suffolk in the Diocese of Ely; on the river Lark, 1¾ mile North of Bury St Edmunds and related that it had 74 houses, a post office, a church and a free school.

Architect Robert Abraham was involved with the expansion of Fornham Hall in the 19th century.

Fornham St Martin Church with King George's playing field is across the way at the south end of B1106 to the village.

The churchyard contains a number of notable burials: Vice-Admiral James Rivett-Carnac CB CBE DSC DL (1891–1970) - Royal Navy officer who became Commander-in-Chief of the New Zealand Division; Major General Sir Harry Ord GCMG CB (1819–1885) - Colonial Governor of several posts including Bermuda, Straits Settlements and Western Australia; and Sir William Gilstrap, Bt. (1816–1896) - Prominent maltster and philanthropist who endowed the Gilstrap library in Newark, Nottinghamshire.