The Golden Valley Railway was a railway company which constructed a branch line from Pontrilas in Herefordshire, England, to Hay on Wye. Pontrilas was on the Great Western Railway main line between Newport and Hereford. The Golden Valley Railway Company opened the first part of its line from Pontrilas to Dorstone in 1881. It was constantly beset with shortage of money, but opened an extension to Hay in 1889. Its directors had grand ideas of extending further to Monmouth and forming part of a long-distance trunk route. It issued misleading promotional material which secured significant investment from the public, but exposure of the falsehoods resulted in collapse.
The line closed in 1898, and the company sold its undertaking to the Great Western Railway in 1899 for £11,000; the capital expended on the line had already amounted to £334,786.
Passenger operation on the line ceased in 1941 and it closed completely in 1957.