Llantwit Major is a town and community in Wales on the Bristol Channel coast. It is one of four towns in the Vale of Glamorgan, with the third largest population after Barry and Penarth, and ahead of Cowbridge. It is 4+1⁄2 miles from Cowbridge, 9 miles from Bridgend, 10 miles from Barry, and 15 miles from Cardiff. It had a population of 9,530 in 2021. Llanilltud Fawr, named for the Llan of Saint Illtud, was home to the Monastery of Illtud and the college known as Bangor Illtyd.