Gamlingay is a village and civil parish in the South Cambridgeshire district of Cambridgeshire, England about 14 miles (23 km) west southwest of the county town of Cambridge.

The 2011 census gives the village's population as 3,247 and the civil parish's as 3,568.

In addition to Gamlingay village, the parish includes the outlying areas of Gamlingay Cinques, Gamlingay Great Heath and Little Heath.

An ancient village listed in the Domesday Book of 1086, the name comes from the Old English Gamelingei, meaning "the enclosure of Gamela's people".

There has been a settlement on the site since the middle Bronze Age and there are signs of occupation from the middle Stone Age. The village may have first been established around a central green south of the High Street (now known as Church Street); a complex of medieval buildings stood at the east end of the green, but only a tithe barn and the house known as 'Emplins' remain today. Another focal point was provided by the crossroads at the other end of Church Street and houses spread to the south and east of the junction. In the 16th and 17th centuries, Gamlingay grew to the east towards Dutter End and west to Green End. By 1801, Gamlingay had a population twice as large as that of the hundred's second-largest parish, Bourn.

Gamlingay is steeped in history, with many listed buildings in the village. The stone for building the church was from a quarry within the village. This quarry then offered the perfect location for an archery range. Being dug into the ground it was a safe area where archery could be practised, and thus was named 'The Butts'. In medieval times it was a requirement that all men over a certain age were capable of using a bow and arrow. The Butts is now a children's play area.

Throughout history, Gamlingay has been a farming village. Most of the village was owned by the Oxford college Merton, and the Cambridge colleges Downing and Clare. Until a few years ago, the houses (subdivisions) at the local village college were named after Merton, Downing and Clare. Downing College acquired the land as a result of a bequest in the will of Sir George Downing, who lived in a mansion, Gamlingay Park, on his Gamlingay estate.

In 1600, 64 houses – comprising much of the village – were destroyed in the "Great Fire of Gamlingay", as described in an extract of a letter from the Privy Council to Sir Thomas Egerton:

"Whereas divers of the Justices of the Peace in the countie of Cambridge have certyfied us the lamentable accydent that hath fallen upon the inhabitantes of Gamlingay in the said countie, by casualltie of fire that happned on the 21St daie of Aprill last, whereby the moste parte of the said towne to the nomber of 76 houses with divers barnes and stackes of corne were suddainlie consumed."

By 1844, Gamlingay had five inns, including the Cock (dating from at least 1588), the Rose & Crown (1622) and the Blue Ball (1770s). The Sultan was built near the station in 1867. At one time, there were 54 pubs in Gamlingay to serve the coach routes from London. It is claimed that the highwayman Dick Turpin rode through the village on his way north.

Gamlingay had a station on the Bedford and Cambridge branch of the London and North Western Railway, which opened in 1862 and shut in 1968 in the Beeching cuts.