The council is one of twenty-two unitary authorities that came into existence on 1 April 1996 under the provisions of the Local Government (Wales) Act 1994.

The first election was held in January 1889 and the majority of the seats were won by the Liberals.

[4] The council formally came into its powers on 1 April 1889, on which day it held its first official meeting at Carmarthen Guildhall (then also known as the Shire Hall).

[6] Construction of a new County Hall started in 1939 but, due to the Second World War, was not completed until 1955.

[11] The first election to the re-established council was held in 1995, initially operating as a shadow authority before coming into its powers on 1 April 1996.

For each ward, councillors are elected to sit on Carmarthenshire County Council.

[28] The council has customer service centres in Ammanford, Carmarthen and Llanelli.