Haverfordwest Priory was a house of Augustinian Canons Regular on the banks of the Western Cleddau at Haverfordwest, Pembrokeshire, Wales. Dedicated to St. Mary and St. Thomas the Martyr and situated on land given by Robert de Haverford, it was first mentioned around 1200. According to William Latham Bevan, “It owned the three churches in Haverfordwest, Haroldston St. Issels adjacent to it, Llanstadwell, Dale, Lambston, Camrose, Llanwynio, St.