Attended the London 1948 Games, his greatest sporting honour came when he was slected as a member of Ireland's athletics team, the first Olympic Games held after the Second World War. O'Cleirigh was named as part of Ireland's men's 4 x 400 metres relay squad. Although he did not ultimately compete in the event, his selection for the Olympic team remains a significant achievement and reflects the high regard in which he was held within Irish Athletics. Following his athletic career, he remained part of a generation that helped establish Ireland's presence in international athletics during the mid-twentieth century. He spent his life in Dublin and passed away in Harold's Cross in August 2001.