Thomas Flanagan was born on October 23, 1930, in Carbury, County Kildare, in the Republic of Ireland.
In 1956, on a visit to Ireland, Archbishop Robert E. Lucey recruited Flanagan to serve as a priest in Texas after his ordination.
He also served as spiritual advisor of the Saint Vincent de Paul Society, Chairman of the Board of the archdiocese's Assumption Seminary, and diocesan chapter chaplain for its Knights of Columbus.
[1] In 1969, Flanagan was appointed as administrator, then pastor, of St. Agnes Parish in Edna, Texas.
Flanagan was awarded a Master of Divinity degree from the Oblate School of Theology in San Antonio in 1979.