Studied in the Sulpician Seminary at Orleans, France. Completed his studies in America, and on 25 May 1793 became the first priest ordained in the United States. Appointed to the Kentucky mission, he labored for many years, forming congregations and building churches. After a sojourn in France from 1819 to 1828, he returned to America and undertook missionary work among the Pottowattomies, being named Vicar-General of Kentucky in 1837. Rector of a French mission in Illinois in 1846. His published works include a history of the Kentucky missions, two Latin poems, and . Father Stephen spent his final years in semi-retirement at the cathedral in Cincinnati, Ohio.
- 21 April 1853 in Cincinnati, Ohio of natural causes
- interred in the cathedral crypt in Cincinnati
- re-interred at the University of Notre Dame, South Bend, Indiana in 1904
- “Father Stephen Theodore Badin”. . Saints.SQPN.com. 20 December 2009. Web. 17 April 2014. <http://saints.sqpn.com/father-stephen-theodore-badin/>