Cathbarr O'Donnell

Cathbarr O'Donnell
Cathbarr Ó Domhnaill
Tomb of Cathbarr and his brother Rory in San Pietro in Montorio
Bornc.1583
Tyrconnell, Ulster, Ireland
Died15 September 1608 (aged 25)
Rome, Papal States
IssueHugh O'Donnell
FatherHugh McManus O'Donnell
MotherIníon Dubh

Cathbarr O'Donnell (Irish: Cathbarr Ó Domhnaill; c.1583 – 15 September 1608) was an Irish nobleman and member of the O'Donnell dynasty of Tyrconnell. The youngest brother of Red Hugh O'Donnell, Cathbarr fought in the Nine Years' War. He married Rosa O'Doherty, sister of Cahir O'Doherty.

In 1607 Cathbarr took part in the Flight of the Earls, leaving Ireland for mainland Europe. He settled in Rome but shortly afterwards died of a fever.

His name is often anglicised as Caffar. It is latinised as Calfurnius on his tomb inscription.