Organization of the Petroleum Exporting Countries, is a permanent, international organization headquartered in Vienna, Austria, was established in Baghdad, Iraq on 10–14 September 1960. Its mandate is to "coordinate and unify the petroleum policies" of its members and to "ensure the stabilization of oil markets in order to secure an efficient, economic and regular supply of petroleum to consumers, a steady income to producers, and a fair return on capital for those investing in the petroleum industry. OPEC comprised twelve members: Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates and Venezuela. According to the United States Energy Information Administration (EIA), OPEC crude oil production is an important factor affecting global oil prices. OPEC sets production targets for its member nations and generally, when OPEC production targets are reduced, oil prices increase. Projections of changes in Saudi production result in changes in the price of benchmark crude oils.

OPEC was formed in 1960 when the international oil market was largely dominated by a group of multinational companies known as the 'seven sisters'. The formation of OPEC represented a collective act of sovereignty by oil exporting nations, and marked a turning point in state control over natural resources. In the 1960s OPEC ensured that oil companies could not unilaterally cut prices. In December 2014, OPEC and the oil men were named in the top 10 most influential people in the shipping industry by Lloyds.

Community content is available under CC-BY-SA unless otherwise noted.