Irish classicist and polymathic scholar.
Mahaffy held a chair in Ancient History at Trinity from 1871, and eventually became Provost in 1914, at the age of 75. He was a distinguished classicist and papyrologist as well as a Doctor of Music. He wrote the music for the Grace in chapel. Mahaffy, a man of great versatility, published numerous works across a range of subjects, some of which, especially those dealing with the 'Silver Age' of Greece, became standard authorities.
He was High Sheriff of County Monaghan for 1900 and a Justice of the Peace for county Dublin. He was president of the Royal Irish Academy from 1911 to 1916.