The school is situated in the village of Drefach and has 580 pupils. The current headteacher is Mr P. W. Williams.
The school promotes the Welsh language, and Welsh history and Welsh culture. Some subjects are available to be taught in the Welsh language if requested, otherwise the lessons are taught in the English language only.
For the 2007-2008 academic year there will be an admission limit of 120 pupils to the first form of the school (Year 7). There is also a Sixth Form College.
The majority of the pupils and staff can speak Welsh. Many staffers live in or near the valley and are thus naturally immersed in all aspects of the life of the community.
Ysgol Y Gwendraeth earned the 2001-2002 Schools Curriculum Award.
The feeder primary schools are Category A schools where Welsh is the language spoken and taught up to the age of seven and where Welsh culture is actively promoted with the assistance of Menter Cwm Gwendraeth, which promotes Welsh and Welsh culture and history. The school also houses the Gerreglwyd Autistic Unit and Annex.