Sleaford is a market town and civil parish in the North Kesteven district of Lincolnshire, England. On the edge of the Fenlands, it is 11 miles north-east of Grantham, 16 mi west of Boston, and 17 mi south of Lincoln. It is the largest settlement in North Kesteven with a population of 19,807 in 2021. Centred on the former parish of New Sleaford, the modern boundaries and urban area include Quarrington to the south-west, Holdingham to the north-west and Old Sleaford to the east. The town is bypassed by the A17 and the A15 roads, which link it to Lincoln, Newark, Peterborough, Grantham, Boston and King's Lynn. Sleaford railway station is on the Nottingham to Skegness and Peterborough to Lincoln lines.