Incorporated on 5th July 1865.
A standard gauge line running 6 miles from the Cambrian Railways to Dinas Mawddwy for the transportation of slate. It opened from 1867 but was closed by 1908, and became a light railway from 1910 worked by the Cambrian Railway. The line later joined the Great Western Railway in 1923, and closed completely in the early 1950’s.

Capital £21,000 in shares, loans of £7,000.