| Location | |
|---|---|
  Gartheiniog Location in Gwynedd | |
| Location | near Aberangell |
| County | Merioneth (now Gwynedd) |
| Country | Wales, UK |
| Coordinates | 52°41′14″N 3°44′39″W / 52.687325032727585°N 3.744051095709508°W grid reference SH 768 102 |
| Production | |
| Products | Slate |
| Type | Quarry |
| History | |
| Opened | 1880 |
| Active | 1881–1917 1920–1937 |
| Closed | October 1937 |
Gartheiniog quarry was a slate quarry served by the Hendre Ddu Tramway. It is located about a mile west of Aberangell in Merioneth (now Gwynedd), North Wales near the confluence of the Nant Maesygamfa and the Afon Angell. It worked the Narrow Vein, the highest-quality slate vein in the Abercorris Group.