Threekingham (sometimes Threckingham) is a village in the North Kesteven district of Lincolnshire, England. It is situated on the A52 Grantham to Boston road, south from Sleaford, and close to the A15 Threekingham Bar roundabout. Mareham Lane, the Roman Road aligned with King Street, crosses the A15 at Threekingham.
The Medieval Stow Fair was held nearby, less than to the south. It is possible that it was the site of the early medieval nunnery founded in the late 7th century by Saint Werburh, dedicated to Saint Æthelthryth, and probably destroyed by the Danes c. 870.
There are ancient earthworks and a mound called Threekingham Beacon to the west of the village. The post-medieval garden features overlie much older earthworks and tumuli. The remains of a moated manor house are in Hall Lane.
There is a Whalebone Arch marking the entrance to Laundon Hall.