The present station is the third to serve the town and dates from 1902,[2] although the South Wales Railway's main line from Swansea to Neyland reached Carmarthen some fifty years earlier.

This was worked by the Great Western Railway from the outset, as the company had by this time absorbed the other lines mentioned (apart from the Llandeilo branch, which remained in LNWR hands until the 1923 Grouping).

From Abergwili Junction northwards, the railway trackbed resumes and is owned by the preserved Gwili Railway which runs preserved trains along part of the Aberystwyth line, through the valley of the River Gwili, from Abergwili Junction, through Bronwydd Arms and Llwyfan Cerrig, to as far as Danycoed en route, close to Cynwyl Elfed.

In June 2019, a plaque was unveiled at the station to commemorate the eight Great Western Railway workers from Carmarthen who lost their lives in the First World War.

[7] To the east, Transport for Wales operate regular services to Swansea, Cardiff Central, Crewe and Manchester Piccadilly.

Great Western Railway currently operate six services per day (Mon-Sat, 4 on Sundays) between this station and London Paddington.

[9] In December 2022, the ORR approved Grand Union to commence a new service from Paddington to Carmarthen in partnership with Spanish rail operator Renfe, for which a fleet of new bi-mode trains will be used.

[10] The service will call at Bristol Parkway, Severn Tunnel Junction, Newport, Cardiff Central, Gowerton and Llanelli en-route to Carmarthen.

These connect with the Stena Line ferry to/from Rosslare Europort in Ireland with a daily morning and evening service in both directions.