Harold Glenn Hamm (born December 11, 1945, in Lexington, Oklahoma) is an American billionaire businessman and pioneer in the oil and gas industry. Raised in a poor family as the 13th of 14 children on a sharecropping farm, he began his career at age 17 as a truck driver for an oil company. He founded his first oil company, Hamm's Inc., in 1967 while studying geology at Oklahoma State University (though he did not complete his degree). That same year, he established what would become Continental Resources, growing it into one of the largest independent oil producers in the U.S. and a major fracking company. As founder, CEO, and Executive Chairman, Hamm built his fortune through innovative drilling techniques, becoming a key figure in the hydraulic fracturing (fracking) revolution that unlocked vast shale oil reserves, particularly in the Bakken Formation, helping make America the world's top oil producer.

Hamm is one of Oklahoma's wealthiest oil executives, with his net worth estimated at US$18.5 billion as of February 2022, ranking him among the world's richest individuals. He has wielded significant political influence as a major donor to Republican causes and advisor to political figures, including serving as an energy advisor to President Donald Trump during the 2016 transition. His personal life includes a high-profile divorce in 2014 from Sue Ann Arnall, resulting in one of the largest settlements in U.S. history at $975 million.

Beyond business, Hamm has engaged in philanthropy supporting education and health initiatives in Oklahoma while advocating for deregulation in the energy sector. Continental Resources has been both praised for job creation and criticized for environmental impacts associated with fracking. As of recent years, Hamm has stepped back from day-to-day operations but remains a dominant figure in the industry, embodying the self-made American success story rooted in the heartland.