St Asaph Grammar School was built in 1877. In 1969, having outgrown its earlier home in a former Prestatyn primary school, Ysgol Glan Clwyd, established in 1956 as the first school of its type with a formal remit to teach through the medium of Welsh, moved into the premises. The original building has been refurbished, with extensions opening in November 2017 at a cost of £16.5m, as part of Welsh Government's 21st Century Schools Programme.

RCAHMW 2010. Updated by Meilyr Powel, RCAHMW. November 2021.

Source: 'Cymreictod', Ysgol Glan Clwyd website; 'Ysgol Glan Clwyd', County Voice, 2019, Issue 1.