Ó Troighthigh (in English: Troy; O'Trohy) is a Gaelic-Irish surname, meaning descendant of foot-soldier.
The Uí Troighthigh were associated with the Kingdom of Corco Modhruadh, an area that was coextensive with the diocese of Kilfenora.
Conchobhar, son of Maelseachlainn, lord of Corca-Modhruadh; and Aicher Ua Traighthech, with many others, were slain by the men of Umhall.
While they originated in County Clare with Aicher Ua Traigthech, a large contingent settled within Clogheen district of County Tipperary and their association with the region perpetuated in the place-name Ballytrehy (Baile Uí Throithigh, or the town of Ó Troithigh).
Doctors in the Uí Troighthigh family were known for their study of medicine and translated many Latin and Greek medical textbooks over the centuries.