Petrus Ua Mórda (Anglicised: Peter O'Mordha, (O')More, or (O')Moore) was Bishop of Clonfert from circa 1150 to 1171.
He appears to have been a member of a family from Ui Maine, one of the oldest and largest kingdoms located in Connacht, Ireland. Ua Mórda was abbot of Grellach dá Iach, the first of three sites inhabited by the Cistercians, and who finally settled at Boyle Abbey. In around 1150 AD, he became Bishop of Clonfert; styled as Bishop of Cluain-fearta-Brenainn or Bishop of Ui Maine.
He was greatly esteemed as "a divine and learned monk". He drowned in the River Shannon (Irish: Abha na Sionainne), near Port-da-Chaineg, on 27 December 1171.
Cotton, Henry (1850). The Province of Connaught. Fasti Ecclesiae Hiberniae: The Succession of the Prelates and Members of the Cathedral Bodies of Ireland. Vol. 4. Dublin: Hodges and Smith. pp. 161–162.
Fryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I., eds. (1986). Handbook of British Chronology (3rd, reprinted 2003 ed.). Cambridge: Cambridge University Press. p. 339. ISBN0-521-56350-X.
Moody, T. W.; Martin, F. X.; Byrne, F. J., eds. (1984). Maps, Genealogies, Lists: A Companion to Irish History, Part II. New History of Ireland. Vol. XI. Oxford: Oxford University Press. p. 324. ISBN0-19-821745-5.
