Arenig railway station stood beneath Arenig Fawr on the Great Western Railway's Bala Ffestiniog Line in Gwynedd, Wales. It served this thinly populated upland area, but its particular purposes were to serve Arenig Granite quarry which opened in 1908 next to the station and to act as a passing loop on the largely single-track route. The railway was the quarry's main carrier and also its main customer, crushed stone being used for track ballast.