The Officer Cadet School, Portsea (sometimes referred to as OCS Portsea) was an officer training establishment of the Australian Army. Established at Portsea in Victoria, Australia, in 1951 to provide training to officer cadets prior to commissioning, for many years OCS provided the Australian Regular Army with the bulk of its junior officers. However, following a review of military training establishments in Australia in the mid-1980s, the school was eventually closed in 1985, as the Royal Military College, Duntroon, assumed sole responsibility for training Army officers.