Ysgol Llanhari is a Welsh-medium school for 3-19 year olds situated in the village of Llanharry, Rhondda Cynon Taf, Wales.

In 1974, the school was located in the county of Mid Glamorgan and had a huge catchment area from Tonteg and Cardiff in the east, all the way to Porthcawl and Maesteg in the west.

Within a few years, it was decided that South Glamorgan pupils would be educated in their own county and in 1978, Ysgol Gyfun Gymraeg Glantaf opened in Cardiff.

Prior to this, Mr Peter Griffiths, father of Ioan Gruffudd, star of such films as Fantastic Four and Wilde served as head from 1989.

Until August 2022, Ms Meinir Thomas served as deputy headteacher, with Ms Catherine Webb, Mr Geoffrey Howell, Mrs Elen George and Mr Marc Evans serving as assistant head teachers.