Fenstanton is a village and civil parish in Cambridgeshire, England, 2 miles (3 km) south of St Ives in Huntingdonshire, a non-metropolitan district of Cambridgeshire and historic county. Fenstanton lies on the south side of the River Ouse.

Known as Stantun in the 11th century, Staunton and Stanton Gisbrit de Gant in the 13th century, the name Fenstanton (and Fennystanton) appeared from the 14th century. The name "Fenstanton" means "fenland stone enclosure".

Lying on the Via Devana, the Roman road that linked the army camps at Godmanchester and Cambridge, Fenstanton was the site of a Roman villa, possibly designed to keep order after an attack on the forces of the IX Legion Hispana, as they retreated from an ambush at Cambridge by Boudicca's tribesmen. The first example of a Roman crucifixion in UK was discovered in a burial in Fenstanton in 2017, when a skeleton of a man was found with a nail through his heel. In 2021, the bones were unearthed.

The inhabitants of Fenstanton rose in support of Hereward the Wake. From his stronghold on the Isle of Ely Hereward led resistance against the Normans causing King William I to assemble a force in Cambridge to deal with the problem. Men were summoned from Huntingdon but they did not pass Fenstanton and escaped with their lives only by swimming across the river.

Fenstanton was listed in the Domesday Book in the Hundred of Toseland in Huntingdonshire; the name of the settlement was written as Stantone in the Domesday Book. In 1086 there was just one manor at Fenstanton. By 1086 there was already a church and a priest at Fenstanton.