 On leaving school, Ó Fátharta spent two years with an acting school with the Abbey Theatre and subsequently twenty years with the Abbey from 1972-1996, while there he acted in plays by John B. Keane, Brian Friel, Tom Murphy, Shakespeare, Chekov, all of his production involvement can be found in the Abbey archives.In 1975 he appeared in a play by Irish playwright Teresa Deevy called "Katie Roche" where he played the part of Jo Mahony.In 1995 Ó Fátharta adapted the seminal novel "Cré na Cille" for the stage and later wrote the screenplay for the film version.