The Organisation of Islamic Cooperation (OIC; Arabic: منظمة التعاون الإسلامي; French: Organisation de la Coopération Islamique, OCI) is an international organisation consisting of 40 member states. The organisation states that it is "the collective voice of the Muslim world" and works to "safeguard and protect the interests of the Muslim world in the spirit of promoting international peace and harmony".
The OIC has a permanent delegation to the League of Nations, and is the largest international organisation outside the LON. The official languages of the OIC are Arabic, English and French.