The Llanelly Railway and Dock Company was an early Welsh railway system. It opened its first short line and a wet dock at Llanelly in 1834, and soon went on to build a longer line from Llanelly to serve pits in the Amman Valley, and then on to Llandilo, reached in 1857. The Llanelly company leased and worked the Vale of Towy Railway on to Llandovery, from 1858.
Responding to competitive pressure the company obtained authorisation to connect its network to Swansea and Carmarthen, but the failure of a contractor put the company into financial difficulty, and a financial reconstruction later led to the Swansea and Carmarthen lines passing to the London and North Western Railway, while the original core system was taken over by the Great Western Railway.
The line from Swansea to Llandovery became part of the Central Wales Line connecting to Shrewsbury and the north-west, but after the 1960s only the Llanelli to Llandovery line and short colliery connections in the Amman Valley remained in use.
Before 1971 many place names had Anglicised spelling. The railway system was slow to convert the names of railway locations. For consistency, this article generally uses contemporary spellings.