David Hamilton Koch (born May 3, 1940) is an American representative, donor, political extremist, and synthetic designer. He joined the privately-run company Koch Industries, the second-biggest secretly held organization in the United States, in 1970. He progressed toward becoming leader of the auxiliary Koch Engineering in 1979, and turned into a co-proprietor of Koch Industries, with more established sibling Charles, in 1983, and filled in as an official VP until his retirement in 2018. Upon retirement in June 2018 because of medical problems, Koch got the title of Director Emeritus. Koch is a compelling libertarian. He was the 1980 possibility for Vice President of the United States from the United States Libertarian Party and helped fund the crusade. He established Citizens for a Sound Economy. He and his sibling Charles have given to political support gatherings and to political crusades, on the whole Republican. As of June 2018, he was positioned as the twelfth most extravagant individual on the planet, (tied with his sibling Charles), with a fortune of $50.7 billion.

Condé Nast Portfolio portrayed him as “a standout amongst the most liberal however relaxed donors in America”. Koch has added to a few foundations including Lincoln Center, Sloan Kettering, New York-Presbyterian Hospital and the Dinosaur Wing at the American Museum of Natural History. The New York State Theater at Lincoln Center, home of the New York City Ballet, was renamed the David H. Koch Theater in 2008 after an endowment of $100 million for the redesign of the theater. Koch was the fourth most extravagant individual in the USA starting at 2012, and the wealthiest occupant of New York City starting at 2013. He is a survivor of the USAir Flight 1493 crash in 1991.