Thomas Joseph Costello (February 23, 1929 – February 15, 2019) was an American prelate of the Catholic Church who served as an auxiliary bishop of Roman Catholic Diocese of Syracuse.
Born in Camden, New York, Costello was ordained to the priesthood on June 5, 1954, at the Cathedral of the Immaculate Conception and served as a priest for 24 years before being consecrated a bishop on March 13, 1978. In addition to serving as auxiliary bishop of Syracuse, he was also named Titular Bishop of Perdices.
In the years before being elevated to bishop, Costello received the title of monsignor from Pope Paul VI in 1965.
He retired on March 23, 2004. He died on February 15, 2019.