The Exxon Mobil Corporation, or ExxonMobil, is an American oil and gas corporation. It is a direct descendant of John D. Rockefeller's Standard Oil company, and was formed on November 30, 1999, by the merger of Exxon and Mobil.

ExxonMobil is the world's second largest publicly traded company when measured by market capitalization after PetroChina. Exxon Mobil's reserves were 72 billion oil-equivalent barrels at the end of 2007 and, at current rates of production, are expected to last over 14 years. The company has 38 oil refineries in 21 countries constituting a combined daily refining capacity of 6.3 million barrels.

While it is the largest of the six oil supermajors with daily production of 3.921 million BOE (barrels of oil equivalent) in 2008, this is only approximately 3% of world production and ExxonMobil's daily production is surpassed by several of the largest state-owned petroleum companies. When ranked by oil and gas reserves it is 14th in the world with less than 1% of the total.

ExxonMobil has been accused by major scientific organizations of waging a misinformation campaign aiming to create uncertainty on the issue of global warming.