O'Malley made his debut on the inter-county scene when he first linked up with the Roscommon junior teams as a dual player.
An All-Ireland medallist with the hurling team at the end of his career, O'Malley made his senior football debut during the 1947-48 league.
He went on to play a key role for Roscommon during a hugely successful era, and won four Munster medals.
[2] As a member of the Connacht inter-provincial teams in both codes, he won three Railway Cup medals as a footballer.
Immediately after his retirement from club activity, O'Malley took charge of the St. Brigid's senior team, guiding them to the championship title in 1969.