Founded in 1815 by Sarah Hopkins, in memory of her brother Samuel (an early proprietor of Blaenavon Ironworks from 1798), St Peter's was the first purpose built school in Wales by an individual proprietor for children of the workforce. It was enlarged in 1849 and 1860. It is the oldest known iron works school in Wales and is an excellent example of 'The Madras School', which was a pioneer of elementary education. Originally consisted of two large halls, one each for boys and girls, with adjacent school masters and mistresses houses. Became the girls' school in 1860 when the boys' school was built. 

Neo-gothic in style similar to that of the neighbouring St Peter's Church. Built of sand stone with slate roof, the school is on a symmetrical plan and has nine bays. There is one storey to the main central block, two storeys to the hipped roof wings at either end and a later extension to the rear.

RCAHMW, 2009. Updated by M. Powel, RCAHMW. August 2023

Source: Cadw Listing Summary no.3150