Glenn Herbert McCarthy (December 25, 1907 - December 26, 1988) was an American oil tycoon. The media often referred to him as "Diamond Glenn" and "The King of the Wildcatters". McCarthy was an oil prospector and entrepreneur who owned many businesses in various sectors of the economy. McCarthy founded the
Shamrock Hotel in Houston, which gained him national fame and inspired the fictional character Jett Rink in
Edna Ferber's 1952 novel
Giant along with its 1956
film adaptation, which starred
James Dean in the role.