NEW, a market-town of England, in the county of Lincoln, on the river Slea, 18 miles S. by E. of Lincoln, and 115 N. by W. of London. It is a neat and prosperous place, consisting of three well-paved streets. The parish church is remarkable for its antiquity and its architecture. It is a large cruciform edifice, and was founded in 1271. The oldest portion, consisting of a tower at the west end, is in the early English style; the spire is of later date; the chancel is in the perpendicular; the aisles and transept in the decorated style; and each of the parts in its own way is very good. Sleaford has also places of worship for Independents and other sects, a grammar school, national schools, and an hospital. The town-hall is a handsome modern building. Quarter sessions and a county court are held here. Pop. 3729.