Thomas Barrett of Meelick was the son of Stephen Barrett Esq. and Celia O'Beirne in Meelick House, Kilmore, Co. Roscommon. His father was a strong farmer, cess collector, and barony constable for Co Leitrim, and Thomas inherited the family farm.
- He is descended from a long line of substantial graziers in the parish of Killummod, near Croghan, Co Roscommon.
- Stiofáin Bairéad (1867-1921) of Conradh na Gaeilge fame was his younger brother.
In 1932, he died at age 70 with his son Stephen J Barrett of Meelick present at death. He was interred in the Finnor Barrett plot at Killappoge Graveyard, Croghan.