| Election Name: | 1940 South Dakota gubernatorial election |
| Country: | South Dakota |
| Flag Year: | 1909 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1938 South Dakota gubernatorial election |
| Previous Year: | 1938 |
| Next Election: | 1942 South Dakota gubernatorial election |
| Next Year: | 1942 |
| Election Date: | November 5, 1940 |
| Nominee1: | Harlan J. Bushfield |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 167,686 |
| Percentage1: | 55.14% |
| Nominee2: | Lewis W. Bicknell |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 136,428 |
| Percentage2: | 44.86% |
| Map Size: | 250px |
| Governor of South Dakota | |
| Before Election: | Harlan J. Bushfield |
| Before Party: | Republican Party (United States) |
| After Election: | Harlan J. Bushfield |
| After Party: | Republican Party (United States) |
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.