Cillen (Cillian, Cillin, Killinus, or Killianus) occurs frequently as a name of saints in the Irish calendars: whether the initials be C.,K., or Q., the name is the same, and derived from Cill ("a cell"):
1. Son of Lubnen, is, commemorated April 14. Colgan (Acta Sanctorum, 473, c. 4) enumerates him among the prelates of Saighir, where he was abbot, and gives his date as A.D. 695. See Lanigan, Eccl. Hist. Ir. 3:140 sq.
2. Commemorated July 3, became abbot of Iona in A.D. 726. For some now unknown reason he was called Droicteach, or the Bridge-maker. He died A.D. 752. See Lanigan, Eccl. Hist. Ir. 3:166, 192; Forbes, Kal. of Scott. Saints, page 301.
3. Commemorated April 19, was the thirteenth abbot of Iona, and succeeded Faelan, A.D. 724. He was called Foda or Fada, the Tall, to distinguish him from his successor, Cillen Droicteach. He died in 726.
4. Bishop of Techtalani, is commemorated on May 27. When St. Patrick came to the region of Meithtire, in Ulster, he is said to have built a church at Teaghtalani and placed it in charge of bishop Cillen.
5. Cillen Ua Colla, abbot of Fathain Mura, now Fahan, is commemorated Jan. 3. He succeeded St. Keliach, and died about 724. See Todd and Reeves, Mart. Doneg. page 7; O'Hanlan, Irish Saints, 1:57.