Grammar school reputedly founded in 1575, but 1632 generally accepted as date of foundation. The school transferred to site on Pen y Cae Road in 1858. It became the county school for boys in 1895 and the girsl school opened in 1922. The school became separate boys and girls in 1945 and mixed in 1967. Became Ysgol Rhiwabon Comprehensive in 1967.
The collection includes a range of material including some admissions registers, governors minutes, photographs and some accounts.