Plymouth City Council is the local authority for the city of Plymouth, in the ceremonial county of Devon, England. Plymouth has had a council since 1439, which has been reformed on numerous occasions. Since 1998 the council has been a unitary authority, being a district council which also performs the functions of a county council; it is independent from Devon County Council.

The council has been under Labour majority control since 2023. It meets at the Council House in the city centre and has its main offices at Ballard House in the Millbay area of the city. The population of the unitary authority is 277,695.

Plymouth was an ancient borough, having been incorporated in 1439. It was reformed to become a municipal borough in 1836, governed by a corporate body officially called the "mayor, aldermen and burgesses of the borough of Plymouth", but generally known as the corporation or town council. When elected county councils were established in 1889, Plymouth was considered large enough for its existing corporation to provide county-level services and so it was made a county borough, independent from Devon County Council.

In 1914 Plymouth absorbed the neighbouring towns of Devonport and East Stonehouse. The enlarged Plymouth was awarded city status on 18 October 1928, after which the corporation's formal title was the "mayor, aldermen and citizens of the city of Plymouth", also known as the city council. The position of mayor was raised to a lord mayor in 1935.

In 1974 Plymouth became a lower-tier non-metropolitan district under the Local Government Act 1972, with Devon County Council providing county-level services to the city for the first time. Plymouth's city status was re-conferred on the reformed district, allowing the council to take the name Plymouth City Council.

Plymouth regained its independence from the county council on 1 April 1998 when it was made a unitary authority following the recommendations of the Banham Commission. The way this change was implemented was to create a new non-metropolitan county of Plymouth covering the same area as the existing district, but with no separate county council; instead the existing city council took on county council functions, making it a unitary authority. This therefore had the effect of restoring the city council to the powers it had held when Plymouth had been a county borough prior to 1974. The city remains part of the ceremonial county of Devon for the purposes of lieutenancy.

As a unitary authority, Plymouth City Council has the responsibilities of both a district council and county council combined. There are no civil parishes in the city. Some functions are carried out in partnership with neighbouring authorities, notably with the city council appointing four members to the Devon and Somerset Combined Fire Authority. The council is also responsible for arranging elections both for its own councillors and for three Parliamentary constituencies: Plymouth Moor View; Plymouth, Sutton and Devonport; and South West Devon.

The council has been under Labour majority control since the 2023 election.