KILDARE and LEIGHLIN, DIOCESE of. - It comprises the Irish county of Carlow and parts of those of Kildare, Leix, Offaly, Kilkenny, Wicklow, and Wexford. K. and L. are suffragans of Dublin; the episcopal residence is in Carlow.
Out of a population of 132,091 inhabitants, the two dioceses together have 122,936 Catholics (1936 census), distributed among 49 parishes, served by 143 diocesan priests and 62 regular clergy, 20 male and 31 female religious communities; in Carlow are both the major seminary (St. Patrick's College) and the minor seminary (St. Mary's, Knockbeg College).
St. Brigida had founded there, beside a large oak tree, her first monastery, hence called Cill-dara (or cell of the oak), and the name was extended to designate the whole district and the diocese. The first bishop appears to have been St. Conleth, consecrated about 490. The bishop of K. was often called abbot-bishop and bishop of Leinster. Besides St. Brigida, the diocese counts among its saints: St. Fiac of Sletty, Conleth, Eimhin of Monastero, Brogan of Clonsast, Aedh of Sletty. In 1678 the ancient diocese of Leighlin, founded by St. Laserian, was permanently united to K.