| Election Name: | 1940 Democratic Senate primary election in Mississippi |
| Country: | Mississippi |
| Flag Image: | Flag of Mississippi (1894-1996).svg |
| Type: | Presidential |
| Ongoing: | no |
| Previous Election: | 1934 United States Senate election in Mississippi |
| Previous Year: | 1934 |
| Next Election: | 1946 United States Senate election in Mississippi |
| Next Year: | 1946 |
| Election Date: | August 27, 1940 |
| Image1: | File:Theodore Bilbo (cropped).jpg |
| Nominee1: | Theodore Bilbo |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 91,334 |
| Percentage1: | 59.32% |
| Nominee2: | Hugh White |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 62,641 |
| Percentage2: | 40.68% |
| Map Size: | 255px |
| U.S. Senator | |
| Before Election: | Theodore Bilbo |
| Before Party: | Democratic Party (United States) |
| After Election: | Theodore Bilbo |
| After Party: | Democratic Party (United States) |
The 1940 United States Senate election in Mississippi was held on November 6, 1940. Incumbent Senator Theodore Bilbo was re-elected to a second term.
On August 27, Bilbo won the Democratic primary election over Governor Hugh L. White with 59.32% of the vote. Bilbo won the November general election without an opponent.