Joseph Stephen O’Leary is an Irish Roman Catholic theologian. Born in Cork, 1949, he studied literature and theology at Maynooth College (BA 1969; DD 1976). He also studied at the Gregorian University, Rome (1972-3) and in Paris (1977–79). Ordained for the Diocese of Cork and Ross in 1973, he was a chaplain at University College Cork (1980–81). He taught theology at the University of Notre Dame (1981–82) and Duquesne University (1982–83) before moving to Japan in August, 1983. He worked as a researcher at the Nanzan Institute for Religion and Culture, Nanzan University, Nagoya (1985–86), where he later held the Roche Chair for Interreligious Research (2015–16). He taught in the Faculty of Letters at Sophia University, Tokyo, from 1988 to 2015.