Mike Grell studied at the University of Wisconsin and the Chicago Academy of Fine Arts. He entered the comics field in 1972, when he became an assistant to Dale Messick on 'Brenda Starr'. He moved to New York a year later, and started working for DC Comics on titles such as 'Aquaman', 'Green Arrow', 'Phantom Stranger', 'Batman' and 'The Legion of Super-Heroes'. He came up with his own creation, 'The Warlord', in 1976. It soon became DC's best-selling title. Mike Grell also created 'Starslayer' in 1978. He took over the 'Tarzan' Sunday newspaper strip in 1981, following in the footsteps of Hal Foster, Burne Hogarth and Russ Manning.
Mike Grell moved from northern Wisconsin to Idaho with his wife Sharon, where he still lives and works.