South Northamptonshire was a local government district in Northamptonshire, England, from 1974 to 2021. Its council was based in the town of Towcester, first established as a settlement in Roman Britain. The population of the Local Authority District Council in 2011 was 85,189.

Northamptonshire is a ceremonial county in the East Midlands of England. It is bordered by Leicestershire, Rutland and Lincolnshire to the north, Cambridgeshire to the east, Bedfordshire, Buckinghamshire, Oxfordshire to the south and Warwickshire to the west. Northampton is the largest settlement and the county town.