Sleaford is a market town and civil parish in the North Kesteven district of Lincolnshire, England. Centred on the former parish of New Sleaford, the modern boundaries and urban area include Quarrington to the south-west, Holdingham to the north and Old Sleaford to the east. The town is on the edge of the fertile Fenlands, 11 mi north-east of Grantham, 16 mi west of Boston, and 17 mi south of Lincoln. Its population of 17,671 at the 2011 Census made it the largest settlement in the North Kesteven district; it is the district's administrative centre. Bypassed by the A17 and the A15, it is linked to Lincoln, Newark, Peterborough, Grantham and King's Lynn.