Career
A rover, O'Halloran made his league debut with Essendon in 1950 but struggled to get regular game time. He finished his VFL career at Footscray, playing 17 games for the club in a season and a half. In 1958, O'Halloran briefly transferred to Yarraville in the Victorian Football Association.
He was granted a permit by the Association, but it was revoked after playing only one game when the Permit Committee realised it had made an error – O'Halloran was 28, but the rules required that a player had to be 27 or less to transfer from the VFL to the VFA, unless was transferring as a coach or met residential criteria, which at that time O'Halloran did not. He returned to Yarraville in 1959 and finished his career there.