The organisation was founded in 1946 in Copenhagen as a global press workers' organisation. Initially broad in representation, it became dominated by communist-aligned unions by 1950, prompting non-communist members to withdraw and later re-establish the International Federation of Journalists in 1952.

Headquartered in Prague during the Cold War, the IOJ was closely linked to Soviet interests and described by the CIA as a propaganda tool. Despite this, some leaders claimed its operations were more nuanced than direct Kremlin control.