Tomás mac Muircheartaigh Ó Ceallaigh (Modern Irish: in Irish pronounced as /'t̪ˠɔmˠaːsˠ mˠak ˈmˠɪɾʲɪçaɾˠt̪ˠiː oː ˈcal̪ˠiː/), O.P., Archbishop of Tuam, 1438 to 1441.
Bishop Ó Ceallaigh was translated from the see of Clonfert in 1438. He was a member of the Ui Maine dynasty of south-east Connacht.
The History of the Popes says he:
was translated to Tuam by the Pope. He is spoken of as being a man eminent for piety and liberality.