It was established in 1970 as the first purpose-built comprehensive school in Wales and closed in 2014.

Because of falling pupil numbers, in 2008 a decision was made to close Llanedeyrn and two other Cardiff comprehensive schools.

Remaining pupils were transferred to Llanishen High School or Cardiff High School, or could apply to attend St Teilo's Church in Wales High School.

St Teilo's took over the school's old site at Roundwood Gardens, Llanedeyrn, after moving from its former location in Penylan.

New state-of-the-art buildings were constructed on the former playing fields.