- an organization founded in 1960 of nations that export large amounts of petroleum: formed to establish oil-exporting policies and set prices.
- Organization of Petroleum-Exporting Countries: an organization formed in 1961 to administer a common policy for the sale of petroleum. Its members are Algeria, Angola, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Ecuador and Gabon were members but withdrew in 1992 and 1995 respectively