Officer Candidate School or Officer Cadet School (OCS) are institutions which train civilians and enlisted personnel in order for them to gain a commission as officers in the armed forces of a country. How OCS is run differs between countries and services. Typically, Officer Candidates are already Bachelor's Degree holders, has a short duration of training (not more than a year) which focuses primarily on military skills and leadership. This is in contrast with service academies which include academic instruction leading to a bachelor's degree.
Officer Cadet School of Australia – Portsea (OCS Portsea) commenced training officers for the Australian Army in 1951 and continued through to the end of 1985. Since OCS Portsea's closure in 1985, all Australian Army Officer training has been conducted at the Royal Military College, Duntroon in Canberra. During the Vietnam War, the Officer Training Unit, Scheyville was used to train and commission National Servicemen as 2nd Lieutenants between 1965 and 1972.
In the Philippines, Officer Candidate School was originally formed out from the defunct School for Reserve Commission or SRC that was established in the 1930s pursuant to the provisions of then Philippine Commonwealth Act Number 1, otherwise known as "The National Defense Act of the Philippines". This was created in preparation for the defense of the Philippines, establishing a 10-year program of training for Filipino Servicemen and Civilian Volunteers (Reserve), and forming the Philippine Army as the main ground forces of the Armed Forces of the Philippines. A transfiguration took place with some military personnel from the Philippine Constabulary being transferred to form the nucleus of the Philippine Army. However, the 10-year program was incomplete by the time World War II broke out in the Pacific and ROSS training was subsequently stopped. Nevertheless, many of its trainees were called to active duty to serve throughout the war mainly with the U.S. Army Forces in the Far East (USAFFE).