The Wemyss and Buckhaven Railway was a railway company that built a line in the county of Fife in Scotland, connecting Buckhaven with the main line railway network at Thornton, and linking with collieries.
It was financed privately by the Wemyss Estate and largely built on Wemyss Estate land, and it opened in 1881.
It was extended to harbours at Methil and Leven in 1884 to give collieries better access to export shipping; the extension line was called the Leven Extension Railway, and was also privately financed. A passenger service was operated between Thornton and Methil.
The line was sold to the North British Railway in 1889.
The railway served the rich mineral resources of the East Fife Coalfield, but that declined after 1930, and passenger carryings fell steeply at the same time. The line was closed to passenger traffic in 1955 and to all except a very limited goods and mineral traffic in 1965. It closed completely in 1980 and there is now no railway activity on the former line.