Agents persons, peoples and institutions
- s. xx–xxi
Ó Coindealbháin (Eoghan) See: Owen Connellan
Ó Coinnialláin (Tadhg) See: Thaddeus Connellan
- c.1645–c.1704
- Corcach
Ó Comhraí (Eoghan) See: Eugene O'Curry
- 1755–1826
- fl. 19th c.
- County Cork
- d. 1779
- Kinsale, Carmelite friary
- c.1739–1773
- d. 2015
Ó Conchubhair (Diarmuid) See: Dermod O'Connor
- d. 1993
Ó Conchubhair (Muiris) ... lawyer See: Maurice O'Connor [lawyer]