(Llan-y-m-Ddyfri, "Church among the Waters"), a municipal borough and market-town of S. Wales, in Carmarthenshire, about 23 miles E.N.E. from Carmarthen, in the valley of the Towy, near the confluence of that river with the Brân. The streets are irregular, and the only buildings worthy of note are, the parish church, several dissenting chapels, some schools, and the Welsh Educational Institution, founded and liberally endowed, in 1848, by Thomas Phillips, Esq. Near the town, on an insulated rock, is the keep of an old castle, built at a very early date, and dismantled by Cromwell. The vestiges of Roman roads, and the discovery of Roman coins, seem to indicate that Llandovery was once a Roman station. Market-days, Wednesday and Saturday. Pop. (1851) 1927.