The Porthmadog, Beddgelert and South Snowdon Railway (PB&SSR) was a 1 ft 11+1⁄2 in (597 mm) narrow gauge railway intended to connect Porthmadog with the North Wales Narrow Gauge Railways link terminus at Rhyd Ddu. Although some of the line was constructed between 1901 and 1906, it never opened and eventually became part of the Welsh Highland Railway.