Swindon Borough Council is the local authority of the Borough of Swindon in the ceremonial county of Wiltshire, England. It was founded in 1974 as Thamesdown Borough Council, and was a lower-tier district council until 1997. In 1997 it was renamed Swindon Borough Council and became a unitary authority, being a district council which also performs the functions of a county council; it is separate from Wiltshire Council, the unitary authority which administers the rest of the county.

The council has been under no overall control since 2026, with the Conservatives as the largest party. It is based at the Civic Offices on Euclid Street.

The town of Swindon was made a municipal borough in 1900 as a merger of the two urban districts of Old Swindon and New Swindon. Swindon was then governed by a body formally called the 'mayor, aldermen and burgesses of the borough of Swindon', generally known as the corporation, town council or borough council.

That first borough of Swindon, and its council, was abolished in 1974 under the Local Government Act 1972, when its area was merged with the neighbouring Highworth Rural District to become a new non-metropolitan district called Thamesdown. Thamesdown was given borough status from its creation, allowing the chair of the council to take the title of mayor. Thamesdown Borough Council was a lower-tier district council, with Wiltshire County Council providing county-level services in the borough.

On 1 April 1997 Thamesdown was made a unitary authority, making it administratively independent from Wiltshire County Council. The way the change was implemented was to create a new non-metropolitan county called Thamesdown covering the same area as the borough, but with no separate county council. Instead, the existing borough council took on county council functions, making it a unitary authority. In June 1996, during the transition period to becoming a unitary authority, the council passed an order that the borough and the new non-metropolitan county would both be renamed Swindon with effect from 1 April 1997 as well. Swindon remains part of the ceremonial county of Wiltshire for the purposes of lieutenancy.

The local authority derives its powers and functions from the Local Government Act 1972 and subsequent legislation. For the purposes of local government, Swindon Borough is a non-metropolitan area of England. As a unitary authority, Swindon Borough Council has the powers and functions of both a non-metropolitan county and district council. In its capacity as a district council it is a billing authority collecting council tax and business rates, it processes local planning applications, and it is responsible for housing, waste collection and environmental health. In its capacity as a county council it is a local education authority, responsible for social services, libraries and waste disposal.

Since 2010, many schools in the area have become academies and are no longer controlled by the council. It was also the owner of Swindon's main bus operator, Thamesdown Transport, until 2017 when it sold the business to the Go-Ahead Group due to issues with funding. Maintenance services are usually contracted to Swindon Commercial Services (SCS), who work in partnership with the council.

The council's principal decision-making body is its cabinet, which comprises the leader and (as of 2026^[update]) nine portfolio-holding members.