Southampton City Council is the local authority of the city of Southampton in the ceremonial county of Hampshire, England. Southampton has had a council since medieval times, which has been reformed on numerous occasions. Since 1997 the council has been a unitary authority, being a district council which also performs the functions of a county council; it is independent from Hampshire County Council.

The council has been under Labour majority control since 2022. It is based at Southampton Civic Centre.

Southampton was an ancient borough, with the earliest known borough charter dating from 1154. Southampton City Council has records in its archives of council meetings as early as 1199. The borough was led by a mayor from the 13th century. In 1447 the borough was given the right to appoint its own sheriff which made it a county corporate, removing it from the jurisdiction of the Sheriff of Hampshire.

In 1836, Southampton was reformed to become a municipal borough under the Municipal Corporations Act 1835, which standardised how most boroughs operated across the country. It was then governed by a body formally called the 'mayor, aldermen and burgesses of the borough of Southampton', generally known as the corporation, town council or borough council.

When elected county councils were established in 1889, Southampton was considered large enough for the existing borough council to also run county-level services, and so it was made a county borough, independent from the new Hampshire County Council. The borough boundaries were enlarged on several occasions.

The borough was granted city status on 11 February 1964, after which the corporation was also known as Southampton City Council.

Southampton was reconstituted as a non-metropolitan district in 1974 under the Local Government Act 1972. It kept the same boundaries (which had last been enlarged in 1967), but the council became a lower-tier district council, with Hampshire County Council providing services to the city for the first time.

In 1997, Southampton City Council regained responsibility for county-level services from Hampshire County Council as part of the 1990s UK local government reforms. The way this change was implemented was to create a new non-metropolitan county of Southampton covering the same area as the existing district, but with no separate county council; instead the existing city council took on county functions, making it a unitary authority. This therefore had the effect of restoring the city council to the powers it had held when Southampton was a county borough prior to 1974. Southampton remains part of the ceremonial county of Hampshire for the purposes of lieutenancy.