Upon graduation, he worked as a teacher in Alberta and later in British Columbia, while coaching the respective schools’ ice hockey teams.
He moved to Switzerland prior to the 2013–14 season, joining the coaching staff of SC Langenthal of the second-tier division National League B (NLB) as an assistant.
[7] He parted ways with Langenthal after the conclusion of the season and was named assistant coach at National League A club Genève-Servette HC on May 19, 2017.
[8] On May 31, 2018, O'Leary was named head coach of the EVZ Academy, the farm team of EV Zug.
[11] The week before, it was announced that he would serve as head coach of Swiss side SCL Tigers from the beginning of the 2021–22 season.