American businessman Charles de Ganahl Koch has an estimated net worth of $47.5 billion in September 2018. He is co-owner, chairman of the board and chief executive officer of Koch Industries Inc., the second-largest privately held company by revenue (with more than $100 billion in sales) in the United States according to a 2010 Forbes survey.

Charles and his borthers David, Frederick and William inherited Koch Industries from their father's after his death. His father, Father, Fred C. Koch (d. 1967), invented the method of turning heavy oil into gasoline. Charles and David bought out William and Frederick for $1.1 billion in 1983. Today the company, in which they both have 42% stakes, has investments in pipelines, refineries, fertilizer, fibers and polymers, forest and consumer products, chemical technology.