John Roland Lloyd Thomas (22 February 1908 – 11 April 1984) was an Anglican priest and the Principal of St David's University College from 1953 to 1975. He was, himself, a graduate of St David's College, gaining a BA from the institution before completing a second BA in Theology at Jesus College, Oxford. He was the first Lampeter graduate to become Principal of St David's. Lloyd Thomas' name lives on at the college in the residential Lloyd Thomas Hall and refectory.