A native of Pittsburgh, Howard Carroll was educated at Duquesne University and later at St. Vincent's Seminary in Latrobe, PA. He was ordained at the University of Fribourg, Switzerland, in 1927, from which he received his doctorate in sacred theology in 1928. He served as a priest in the diocese of Pittsburgh until 1938, when he joined the NCWC as assistant general secretary under Msgr. Michael J. Ready. In 1944, when Ready was consecrated bishop of Columbus, Carroll was promoted as the third General Secretary of the organization. He left the NCWC at the end of 1957 to receive his episcopal consecration, and served as Bishop of Altoona-Johnstown from 1957 until 1960, when he died of a stroke.