|Irish name||Liam Ó Cealleacháin|
|Died||16 January 1946 (aged 77)
|*Inter County team apps and scores correct as of 13:46, 3 May 2015.|
Born in Cork, O'Callaghan first arrived on the inter-county scene at the age of twenty-four when he first linked up with the Cork senior team. He made his senior debut during the 1892 championship. O'Callaghan immediately became a regular member of the team and won one All-Ireland medal and one Munster medal. In 1892 O'Callaghan captained the team to the All-Ireland title.
Throughout his career O'Callaghan made just two championship appearances. He retired from inter-county hurling following the conclusion of the 1893 championship.