Ysgol Eifionydd, Porthmadog is a bilingual comprehensive school. The majority of its students speak Welsh as a first language and receive their education through the medium of Welsh. The school is located next to the Welsh Highland Heritage Railway in Porthmadog.
There were 487 pupils at the school in 2006, 534 in 2005 and had 369 pupils on roll in 2015.
According to the latest Estyn inspection report, 68% of pupils come from Welsh speaking homes.
The school is over a century old. One of its most famous ex-students was the poet and scholar, T. H. Parry-Williams who first attended the school aged 11 in 1898. Previously it was a grammar school; and was called Ysgol Ganolradd Porthmadog.
Rob Piercy, a successful local artist, was previously the art teacher at Ysgol Eifionydd.
The age of the pupils is 11-16 years of age and the pupils are lead by Mr Dewi Rhys Bowen as the head master.