Llanelli (meaning "Church of St Elli"; ), the largest town in both the county of Carmarthenshire and the preserved county of Dyfed, Wales, sits on the Loughor estuary on the West Wales coast, approximately west-north-west of Swansea and south-east of the county town, Carmarthen. The town is famous for its proud rugby tradition and is a centre of tinplate production. In the mid 20th century, Llanelli was the largest town in the world where more than half the population spoke a Celtic language. It is ranked the 7th largest urban area in Wales. According to the 2001 UK Census returns, 29.69% of Llanelli town residents could speak the Welsh language. Llanelli is also surrounded by a number of villages and communities in the Llanelli Rural district. Some of these communities, more notably those that immediately surround the town, are often unofficially referred to as Llanelli.
Historically a mining town, Llanelli grew significantly in the 18th century and 19th century with the mining of coal and later the tinplate industry and steelworks. Many of these industries were served by the Llanelly and Mynydd Mawr Railway which opened in 1803.
Llanelli became such a significant regional producer of tin that it was referred to as "Tinopolis" by the latter half of the 19th century. The closure of coal mines and competition from overseas steel plants meant that Llanelli, like many other towns in southern Wales, saw significant and sustained economic decline from the late 1970s.
People from Llanelli are sometimes nicknamed "Turks". The origin of this name is uncertain. One theory is that many Turkish sailors once called at the port of Llanelli during their voyages.