Iasiello, OFM, USN (born 6 September 1950) is a Roman Catholic priest, and is a retired American Navy officer who served as the 23rd Chief of Chaplains of the United States Navy from 2003 to 2006.
He is a well known Just War theorist, and his PhD dissertation is entitled: Jus In Bello: Key Issues for a Contemporary Assessment of Just Behavior in War.
For 18 months after his retirement from the Navy, he was the president of Washington Theological Union.
He accepted a position as a Professor of Humanities at Pontifical College Josephinum in Columbus, Ohio, in 2010.