Ysgol Dyffryn Nantlle is a bilingual secondary school for pupils aged between 11 and 18 years.

The school serves the village of Penygroes and the surrounding rural area.

[2] 78 per cent of pupils come from homes in which Welsh is the main language of the household.

[citation needed] On the school's badge, the words 'Delfryd Dysg Cymeriad' are inscribed, which translates to "The ideal of education is to build character" or more concisely "Education Builds Character".

[3] There are four registration classes in each school year, Y, D, N and P. There are also four school houses, Silyn, Dulyn, Llifon and Llyfnwy, which draw their names from local rivers and lakes.