The Forest of Dean Railway was a railway company operating in Gloucestershire, England. It was formed in 1826 when the moribund Bullo Pill Railway and a connected private railway failed, and they were purchased by the new company. At this stage it was a horse-drawn plateway, charging a toll for private hauliers to use it with horse traction. The traffic was chiefly minerals from the Forest of Dean, in the Whimsey and Churchway areas, near modern-day Cinderford, for onward conveyance from Bullo Pill at first, and later by the Great Western Railway.
When the South Wales Railway was proposed in 1844, the FODR was awarded £15,000 to modernise its line and make a broad gauge edge railway in connection; the FODR was slow to implement this and in 1849 the South Wales Railway purchased the FODR outright, making it a branch of its own network. The line was steeply graded and difficult to work, and it was often congested due to heavy traffic.
In 1907 passenger traffic was instituted using railmotors, a low-cost means of carrying light passenger traffic, and for some time this was very successful. Trains ran from Whimsey, later extended northward to Drybridge on a contiguous line built by the GWR. Newnham was the main line junction station, although some branch trains ran through to Gloucester. As motor bus services became dominant, the passenger services became unprofitable and they were withdrawn in 1958. The network was closed completely in 1967 as mineral traffic ceased.