Llanidloes High School is an 11 to 18 mixed, community school maintained by Powys local authority. It is an English-medium school with significant Welsh provision. The school is situated in the small town of Llanidloes and serves a large, mainly rural, catchment area. The school shares its campus with a primary school. The Autistic Spectrum Disorder centre for North Powys is located at the school. There are 529 pupils on roll with 72 in the sixth form.