A Capuchin foundation, this modest nineteenth century church built of sandstone and granite was constructed in 1875-6. The building was sympathetically extended in 1923 and a new presbytery added after the Second World War. 

In the late nineteenth century there was a small Catholic community in Abertillery, primarily made up of Irish immigrants working in the local mines. Two local women, Mrs W. H. Brewer and her daughter, were driving forces behind the establishment of a Catholic mission. Mass was said in a public house while funds for a church were raised. The building was completed in 1876, and was used during the week as a school. Its original architect has not been established, but the design bears some similarities with Paul Andre’s Our Lady of the Angels at Cwmbran.

There was no resident priest until 1908. In 1922 a £1500 legacy from John Lancaster, colliery owner, enabled extensive alterations, including the extension of the nave by three bays and the building of a gallery, baptistery and Lady Chapel (builder Stephen Albert Williams of Abertillery).

Reference: The Taking Stock Project entry for St Mary's- an architectural and historical review of Catholic churches and chapels in England and Wales.