Northamptonshire County Council was the county council for Northamptonshire in England.
It was initially created in 1889 under the Local Government Act 1888, with its functions being substantially reformed in 1974 under the Local Government Act 1972.
The council was abolished in 2021, with the area split into North Northamptonshire and West Northamptonshire.
Elections to Northamptonshire County Council were held every four years.
The leaders of the council from 2005 until the council's abolition in 2021 were: