Son of an Irish immigrant and a mixed-race slave, Healy was educated at Boston College and ordained for the Diocese of Boston in 1854. His African descent was known but not publicized and he did not identify himself as black; this both permitted him to rise within the American Church and minimized the impact of his accomplishments as an African-American cleric. (Thus Augustine Tolton is sometimes considered to be the first "black" Catholic priest.) Healy served as bishop of Portland, Maine, from 1875 until his death in 1900.