The 1990 South Dakota gubernatorial election took place on November 6, 1990, to elect a Governor of South Dakota. Republican Governor George S. Mickelson was re-elected, defeating Democratic nominee Bob L. Samuelson. As of 2022, this is the last time Oglala County and Todd County voted for a Republican gubernatorial candidate. Mickelson died in a plane crash near Zwingle, Iowa on April 19, 1993.