O'Leary ranks as one of the
finest long distance runners in Crusader history. Affectionately
known by teammates as "Mouse," his unassuming manner belied the
discipline and dedication of his training. His career was
interrupted due to World War II, during which he served with
distinction, being awarded the Bronze Star for heroism.
O'Leary's achievements for the Crusaders include three New England Championships in the two-mile and three-mile events. In addition, he won the silver medal in the 1946 IC4A Eastern Championship two-mile race. He capped his career with a sensational performance at the National Championships of 1946, where he finished second in the nation in the 5000-meter and 10,000-meter events in both track and cross country.