Occidental Petroleum Corporation ("Oxy") is an international petroleum exploration and development company headquartered in the Westwood district of Los Angeles.

It has also had interests in other forms of energy such as coal, and the production of other minerals such as phosphates.

For many years it was headed by the late Armand Hammer, who was noted for his long-term friendly relationship with the Soviet Union, which has made the company controversial. Its coal interests were represented for many years by attorney and former U.S. Senator Albert Gore, Sr., among others. Gore, who had a long-time close friendship with Hammer, became the head of its subsidiary Island Creek Coal Company upon his (forced) retirement from the Senate. Much of Oxy's coal and phosphate production was from Tennessee, the state Gore represented in the Senate, and Gore owned shares of stock in the company, which are now controlled by his son, former Vice President Albert Gore, Jr.. This relationship was also alleged to have been the basis of the leasing of the mineral rights to the Gore family farm in Smith County, Tennessee; however it must be noted that this region has long been noted for the production of zinc and the Gores are hardly alone in having the mineral rights to their property thusly leased.

In 2005, Occidental Petroleum and partner Liwa won eight out of fifteen exploration spots on the EPSA-4 auction, making both companies among the first to enter the Libyan market since the United States lifted its embargo on that country.