[1] Fay was born in Dublin, where he attended Belvedere College.
[2] He worked for a time in the 1890s with a touring theatre company in Ireland, Scotland, and Wales.
When he returned to Dublin, he worked with his older brother Frank, staging productions in halls around the city.
[3] After a falling-out with the Abbey directors in 1908, the brothers emigrated to the United States to work in theatre there.
One of his most notable film roles was as Father Tom in Carol Reed's Belfast-set Odd Man Out (1947), whose cast was dense with actors from the Abbey Theatre.