The Gwili Steam Railway (Welsh: Rheilffordd Ager Y Gwili) operates a standard gauge preserved railway from Abergwili Junction (near Carmarthen) in South Wales along a short section of the former Carmarthen to Aberystwyth railway closed for passenger traffic in 1965 and lifted in 1973.
The Gwili railway was launched in 1975 and by 1978 had saved 0.5 miles of track and was running an initial steam hauled service. Since then the railway has expanded to Danycoed and the company continues to hope to expand to Llanpumpsaint. Currently, the railway is working south towards Carmarthen. The locomotive stock of the Gwili railway is unusual in that in mostly represents local industrial and wartime operations rather than mainline services.
- 71516 War Department 0-6-0 saddle tank built in 1944. In working order on passenger trains.
- 7058 Robert Stephenson and Hawthorns 0-4-0 saddle tank built in 1942. In use and is used a percy for Thomas the Tank Engine Events.
- 2201 Andrew Barclay 0-4-0 saddle tank built in 1945. Stored awaiting Overhaul.
- 5272 Hunslet Ltd austerity locomitive built in 1945. Recently returned to traffic following an extensive restoration.
- 1914 Avonside Engine Company colliery engine built in 1914 and a long term restoration project.
- 02 101 British Rail Class 02 shunting engine
- D2178 British Rail Class 03 shunting engine
- 421702 Trecatty - Ruston and Hornsby industrial engine
- 27658 North British Locomotive Company shunting engine built for British Steel Landore
- 27878 North British Locomotive Company shunting engine built for British Steel East Moor steelworks and later at the tinplate works at Velindre near Swansea
- 207103 Ruston and Hornsby industrial engine used at Bedwas coke ovens by British Benzol
- 393302 Ruston and Hornsby industrial engine built in 1955 and used at the Aluminium Wire and Cable Company in Swansea
- The Gwili railway is also the only railway in Wales to operate vintage railway coaches on it service trains.
- TVR 145. Having its chicken droppings cleaned out but no major restoration work will start yet
- TVR 220. In service and is sometimes attatched to passenger trains
- GWR 216. Undergoing restoration, a new underframe has been made up and the bogies, wheels and springs have been fitted and completed to, new platework is being fitted to the body currently
- GWR 793. Stored awaiting restoration which will start once 216 is complete