Marc Rich (born Marcell David Reich; December 18, 1934 – June 26, 2013) was a Belgian-American commodities trader, financier, and businessman. He founded the commodities company Glencore, and was later indicted in the United States on federal charges of tax evasion, wire fraud, racketeering, and selling Iranian oil to Israel during the Iran hostage crisis. He fled to Switzerland at the time of the indictment and never returned to the United States.

He received a widely criticized presidential pardon from President Bill Clinton, on his last day in office. Rich had donated large sums to Israeli officials and organizations, which had pleaded extensively on his behalf. Rich's ex-wife Denise had also made donations to the Democratic Party.

Rich was born in 1934 to a Jewish family in Antwerp, Belgium. In 1941 his parents emigrated with their son to the United States to escape the Nazis. They traveled via Vichy France, Spain, Portugal, and the liner Serpa Pinto.

His father opened a jewelry store in Kansas City, Missouri, then moved the family to Queens, New York City in 1950, where he started a company that imported Bengali jute to make burlap bags, and later started a business trading agricultural products and helped found the American Bolivian Bank (Banco Boliviano Americano S.A). Rich attended high school at the Rhodes Preparatory School in Manhattan. He later attended New York University, but dropped out after one semester to work for Philipp Brothers (now known as Phibro LLC) in 1954 where he worked with Pincus Green.

At Philipp Brothers, he eventually became a dealer in metals, learning about the international raw materials markets and commercial trading with poor, third world nations. He helped run the company's operations in Cuba, Bolivia, and Spain. In 1974, he and co-worker Pincus Green set up their own company in Switzerland, Marc Rich + Co. AG, which would later become Glencore Xstrata Plc. Nicknamed "the King of Oil" by his business partners, Rich was said to have expanded the spot market for crude oil in the early 1970s, drawing business away from the larger established oil companies that had relied on traditional long-term contracts for future purchases. As Andrew Hill of the Financial Times put it, "Rich's key insight was that oil – and other raw materials – could be traded with less capital, and fewer assets, than the big oil producers thought, if backed by bank finance. It was this leveraged business model that became the template for modern traders, including Trafigura, Vitol, and Glencore".

His tutelage under Philipp Brothers afforded Rich the opportunity to develop relationships with various dictatorial régimes and embargoed nations. Rich would later tell biographer Daniel Ammann that he had made his "most important and most profitable" business deals by violating international trade embargoes and doing business with the apartheid regime of South Africa. He also counted Fidel Castro's Cuba, Marxist Angola, the Nicaraguan Sandinistas, Muammar Gaddafi's Libya, Nicolae Ceaușescu's Romania, and Augusto Pinochet's Chile among the clients he served. According to Ammann, "he had no regrets whatsoever.... He used to say 'I deliver a service. People want to sell oil to me and other people wanted to buy oil from me. I am a businessman, not a politician.'"

Later, following the overthrow of Mohammad Reza Pahlavi, the Shah of Iran, during the Iranian Revolution in 1979, Rich used his special relationship with Ayatollah Khomeini, the leader of the revolution, to buy oil from Iran despite the American embargo. According to Forbes Magazine, Asadollah Asgaroladi was also the secret business partner of Rich in helping bypass U.S. sanctions against Iran after the Iranian revolution. Iran would become Rich's most important supplier of crude oil for more than 15 years. Rich sold Iranian oil to Israel through a secret pipeline. Due to his good relationship with Iran and Ayatollah Khomeini, Rich helped give Mossad's agents contacts in Iran.

He popularised the use of letters of credit in the oil trade.