Born as Bertha Bowman, she converted to the Roman Catholic Church and joined the Franciscan Sisters of Perpetual Adoration of La Crosse, Wisconsin. She was educated at Viterbo University in La Crosse, Catholic University of America, and Boston College, where she was a scholar of William Faulkner. She gave inspirational talks and appeared on 60 Minutes with Mike Wallace.  A number of schools were named in her honor,including Xavier University of Louisiana's Institution for Black Catholic Studies. 
Sister Bowman told Mike Wallace on 60 Minutes: "I think the difference between me and some people is that I'm content to do my little bit. Sometimes people think they have to do big things in order to make change. But if each one would light a candle we'd have a tremendous light".
- Bowman, Sr. Thea, Franciscan Sisters of Perpetual Adoration (FSPA), Families, Black and Catholic, Catholic and Black (1985)
- Cepress, Sr. Celestine, FSPA (ed.), Sister Thea Bowman, Shooting Star; selected writings and speeches, La Crosse, Wisconsin, FSPA (1999)
- Forthcoming full biography of Thea Bowman. Thea's Song: The Life and Work of Thea Bowman (Orbis Books, Feb. 2010)