David Hamilton Koch was an American businessman, political activist, philanthropist, and chemical engineer. In 1970, he joined the family business: Koch Industries, the second largest privately held company in the United States. He became president of the subsidiary Koch Engineering in 1979 and became a co-owner of Koch Industries in 1983. Koch served as an executive vice president of Koch Industries until he retired due to health issues in 2018.

Koch Industries, Inc. is an American multinational conglomerate corporation based in Wichita, Kansas, and is the second-largest privately held company in the United States, after Cargill. Its subsidiaries are involved in the manufacturing, refining, and distribution of petroleum, chemicals, energy, fiber, intermediates and polymers, minerals, fertilizer, pulp and paper, chemical technology equipment, cloud computing, finance, raw materials trading, and investments. Koch owns Flint Hills Resources, Georgia-Pacific, Guardian Industries, Infor, Invista, KBX, Koch Ag & Energy Solutions, Koch Engineered Solutions, Koch Investments Group, Koch Minerals & Trading, and Molex. The firm employs 122,000 people in 60 countries, with about half of its business in the United States.