The Festiniog & Blaenau Railway (F&BR) was a narrow gauge railway built in 1868 to connect the town of Blaenau Ffestiniog in Wales with the slate quarries around Tanymanod and the village of Llan Ffestiniog, 3+1⁄2 miles (5.6 km) to the south. At Blaenau Ffestiniog it made a direct connection with the Festiniog Railway (FR) with which it was closely associated during its fifteen-year life. The railway was purchased by the Bala and Festiniog Railway in 1883 and converted to 4 ft 8+1⁄2 in standard gauge to extend the Bala Ffestiniog line, a branch of the GWR's line from Ruabon to Barmouth.

Blaenau Ffestiniog is a town in Gwynedd, Wales. Once a slate mining centre in historic Merionethshire, it now relies much on tourists, drawn for instance to the Ffestiniog Railway and Llechwedd Slate Caverns. It reached a population of 12,000 at the peak development of the slate industry, but fell with the decline in demand for slate. The population of the community, including the nearby village Llan Ffestiniog, was 4,875 at the 2011 census: the fourth most populous in Gwynedd after Bangor, Caernarfon and Llandeiniolen. The population not including Llan is now only about 4,000.