The Bhopal disaster, also referred to as the Bhopal gas tragedy, was a chemical accident on the night of 23 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh, India. The industrial disaster is considered the world's worst in history. Over 500,000 people were exposed to methyl isocyanate (MIC) gas. The highly toxic substance made its way into and around the small towns located near the plant.

Estimates vary on the death toll. The official immediate death toll was 2,259. In 2008, the Government of Madhya Pradesh had paid compensation to the family members of 3,787 victims killed in the gas release, and to 574,366 injured victims. A government affidavit in 2006 stated that the leak caused 558,125 injuries, including 38,478 temporary partial injuries and approximately 3,900 severely and permanently disabling injuries. Others estimate that 8,000 died within two weeks, and another 8,000 or more have since died from gas-related diseases.The owner of the factory, UCIL, was majority owned by the Union Carbide Corporation (UCC), with Indian Government-controlled banks and the Indian public holding a 49.1 percent stake. In 1989, UCC paid $470 million (equivalent to $871 million in 2020) to settle litigation stemming from the disaster. In 1994, UCC sold its stake in UCIL to Eveready Industries India Limited (EIIL), which subsequently merged with McLeod Russel (India) Ltd. Eveready ended clean-up on the site in 1998, when it terminated its 99-year lease and turned over control of the site to the state government of Madhya Pradesh. Dow Chemical Company purchased UCC in 2001, seventeen years after the disaster.

Civil and criminal cases filed in the United States against UCC and Warren Anderson, UCC CEO at the time of the disaster, were dismissed and redirected to Indian courts on multiple occasions between 1986 and 2012, as the US courts focused on UCIL being a standalone entity of India. Civil and criminal cases were also filed in the District Court of Bhopal, India, involving UCC, UCIL, and UCC CEO Anderson. In June 2010, seven Indian nationals who were UCIL employees in 1984, including the former UCIL chairman, were convicted in Bhopal of causing death by negligence and sentenced to two years imprisonment and a fine of about $2,000 each, the maximum punishment allowed by Indian law. All were released on bail shortly after the verdict. An eighth former employee was also convicted, but died before the judgment was passed.

Union Carbide Corporation is an American chemical corporation wholly owned (since February 6, 2001) by Dow Chemical Company. It currently employs more than 2,400 people. Union Carbide produces chemicals and polymers that undergo one or more further conversions by customers before reaching consumers. Some are high-volume commodities and others are specialty products meeting the needs of smaller markets. Markets served include paints and coatings, packaging, wire and cable, household products, personal care, pharmaceuticals, automotive, textiles, agriculture, and oil and gas. The company is a former component of the Dow Jones Industrial Average.Founded in 1917 as the Union Carbide and Carbon Corporation, from a merger with National Carbon Company, the company's researchers developed an economical way to make ethylene from natural gas liquids, such as ethane and propane, giving birth to the modern petrochemical industry. The company divested consumer products businesses Eveready and Energizer batteries, Glad bags and wraps, Simoniz car wax and Prestone antifreeze. The company divested other businesses before being acquired by Dow including electronic chemicals, polyurethane intermediates, industrial gases (Linde) and carbon products.