Grantham (pronounced ) is a market town within the South Kesteven district of Lincolnshire, England. It bestrides the London to Edinburgh East Coast Main Line railway and the River Witham, and is bounded to the west by the A1 main north-south road.
Grantham is about south of the city and county town of Lincoln, and about east of the city of Nottingham. The resident population at the 2001 Census was 34,592 in about 18,000 households, excluding the adjacent village of Great Gonerby.
The town is best known as the birthplace of former prime minister Margaret Thatcher, and the place where Isaac Newton went to school, at The King's School. It is close to an ancient Roman road, and was the scene of Oliver Cromwell's first advantage over Royalists during the English Civil War at Gonerby Moor. Grantham is also notable for having the first female police officers in the United Kingdom, notably Edith Smith in 1914, and producing the first running diesel engine in 1892, and the UK's first tractor in 1896.