Fr. Patrick Barrett S.J. was the son of Celia Dillon of Ballaghaderreen and Michael Barrett Esq. of Finnor. He was raised at Finnor house, the home of his grandfather John Barrett Esq.
- He was named for his uncle, Patrick Barrett Esq. of Carrick-on-Shannon.
- Stiofáin Bairéad of Conradh na Gaeilge was his first cousin.
On 5 October 1883, he entered the Jesuit Order at Milltown Park, Dublin and was ordained and was professed on 15 August 1900.
He served as a chaplain during the Great War (WWI) and was for many years Director of retreats at Rathfarnham Castle.
He died at Milltown Park in 1942 and was interred at Glasnevin Cemetery following High Requiem Mass at St Francis Xavier Church (where he had been ordained in 1897). The following relatives were recorded as chief mourners at his funeral: Rev. C. Barrett SJ Clongowes Wood College, Sr. M Wenesclaus, Mrs J. and Mrs K. Barrett, the Misses S. & M. Barrett, Mr & Mrs F. Conroy, and Mr P Moran.
A portrait of Fr. Barrett, painted by Sean Dixon was presented to the Jesuit community at Rathfarnham Castle by the staff of Maguire & Gatchell Ltd Dawson St in 1942.