O'Leary also served as the lacrosse and men's soccer coach in the early club years. He was the first varsity men's lacrosse coach and completed his coaching career in 1988. He coached for Notre Dame in the '70s and '80s when lacrosse was still a club sport. During his time as coach, he led the Irish to a pair of division titles in the Midwest Club Lacrosse Association.
After a four-year prep career at East Meadow High School in New York, O'Leary played lacrosse at Nassau Community College for one season where he helped the team to the national junior college championship in 1967. He twice received All-America honors while attending SUNY-Cortland, and he was selected to play in the North-South All-Star game.
A native of East Meadow, N.Y., O'Leary received his associate degree from Nassau Community College in 1968 and his bachelor's degree from Cortland State in 1971. He went on to earn his master's degree from Notre Dame in 1977. O'Leary is married to the former Linda Hempel and they have four children: Megan, Erin, Daniel and Kevin.