Groes-faen is a village approximately three miles south of Llantrisant in the county borough of Rhondda Cynon Taf, Wales.

The opening of the Bute & Mwyndy iron ore works during the 1850s had a huge impact on the small hamlet of Groes Faen.

The village centre was the pub The Dynefor Arms, and the cottages surrounding it.

In the seventies, the nearby Brofiscin Quarry was used as a dump for toxic chemicals.

[1] In 2007 research began to assess the potential environmental impact of seepage from the Quarry.