The 1940 South Dakota gubernatorial election was held on November 5, 1940. Incumbent Republican Governor Harlan J. Bushfield sought re-election to a second term. After winning the Republican primary by a large margin, he faced Democrat Lewis W. Bicknell, former Day County State's Attorney, in the general election. Though Bushfield underperformed Republican presidential nominee Wendell Willkie, who won the state in a landslide, he nonetheless defeated Bicknell by a wide margin to easily win re-election.