| Country: | Wales |
| Official Name: | Garneddwen |
| Coordinates: | 52.662°N -3.829°W |
| Static Image Name: | Garneddwen - geograph.org.uk - 213903.jpg |
| Static Image Caption: | Garneddwen |
| Community Wales: | Corris |
| Unitary Wales: | Gwynedd |
| Constituency Welsh Assembly: | Dwyfor Meirionnydd |
| Constituency Westminster: | Dwyfor Meirionnydd |
| Post Town: | MACHYNLLETH |
| Postcode District: | SY20 |
| Postcode Area: | SY |
| Dial Code: | 01654 |
| Os Grid Reference: | SH763088 |
Garneddwen (also known as Garnedd-Wen; English: white [[cairn]]) is a hamlet in the south of the county of Gwynedd, Wales. It lies in the historic county of Merionethshire/Sir Feirionnydd, in the valley of the Afon Dulas.
It consists primarily of a single row of terraced houses, built for the workers at Aberllefenni Slate Quarry. The hamlet was named after a large cairn ("carnedd" in Welsh) that was to be found in a field below the farm of the same name up to Victorian times.[1]
Sarn Helen, a Roman road which connected the north and south parts of Roman Wales, probably ran through the hamlet.
Nearby is Fronwen, built as a family home by the quarry manager Robert Hughes (1813–1882) and his wife Jane née Deakin (1822–1906). They had four sons who were born in this house :
Garneddwen railway station was a station on the former Corris Railway, a narrow gauge railway which ran from to . The station was open from 25 August 1887,[2] until the end of passenger services, in December 1930. The Corris Railway closed completely on 20 August 1948,[3] and the track was lifted between and (through Garneddwen, which lies in the middle) in November 1948. The former railway's trackbed at Garneddwen is now an access road for the hamlet.
The hamlet gives its name to the Garnedd-Wen Formation, a thick rock strata that runs from Tywyn to Dinas Mawddwy and was first identified close by the settlement.[4]