Jovan Marinović was a law graduate, and a lawyer before the Second World War. He became a member of the Communist Party of Yugoslavia in 1931, and in 1932–1933 he was the secretary of party leadership at the University of Belgrade. In 1934, Marinović became secretary of the Local Committee of the Communist Party of Yugoslavia for Belgrade, a member of the regional committee of the Communist Party of Serbia for Serbia, and a delegate of the Central Committee of the Communist Party of Yugoslavia to organise the Provincial Conference of the Communist Party of Yugoslavia for Vojvodina. He took part in the National Liberation War from its very beginning. During the Second World War, Marinović was a member of the Politelodel, and later a commissar of the Officers’ School at the Supreme Headquarters of the National Liberation Army and the Partisan units of Yugoslavia. Marinović was also a lecturer and leader of the Central Committee of the Communist Party of Yugoslavia and the Provincial Committee of the Communist Party of Yugoslavia for Serbia during 1943 and 1944. After the Second World War, Marinović was on various duties in Belgrade – Director of Radio Belgrade, Chairman of the Radio Committee of the Government of the Federal Republic of Yugoslavia, Assistant Federal Minister, Secretary of the Federal Executive Council, Director of Tanjug, and Secretary of the Federal Assembly for Information.