| Election Name: | 1978 United States Senate election in Mississippi |
| Country: | Mississippi |
| Flag Image: | Flag of Mississippi (1894-1996).svg |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1972 United States Senate election in Mississippi |
| Previous Year: | 1972 |
| Election Date: | November 7, 1978 |
| Next Election: | 1984 United States Senate election in Mississippi |
| Next Year: | 1984 |
| Image1: | File:Thad Cochran 1977 Congressional photo.jpg |
| Nominee1: | Thad Cochran |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 267,302 |
| Percentage1: | 45.29% |
| Map Size: | 255px |
| U.S. Senator | |
| Before Election: | James Eastland |
| Before Party: | Democratic Party (United States) |
| After Election: | Thad Cochran |
| After Party: | Republican Party (United States) |
| Image3: | File:JFK and Charles Evers (cropped).jpg |
| Nominee3: | Charles Evers |
| Party3: | Independent |
| Popular Vote3: | 133,646 |
| Percentage3: | 22.64% |
| Nominee2: | Maurice Dantin |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 187,541 |
| Percentage2: | 31.77% |
The 1978 United States Senate election in Mississippi was held on November 7, 1978. Incumbent Democratic U.S. Senator James Eastland decided to retire.
Republican Thad Cochran won the open seat, becoming the first Republican to win a U.S. Senate election in Mississippi since the end of Reconstruction in 1881. It was also the first time since 1877 that a Republican won this Senate seat.
Evers was the first African American elected since the Reconstruction era to be mayor in any Mississippi city, in 1969. He ran as an independent, and as a result his campaign divided the Democrats and allowed Cochran to win the Senate seat with a 45 percent plurality.[3] This made Cochran the first Republican in a century to win a statewide election (other than a presidential election) in Mississippi.[4] Eastland resigned on December 27, 1978 to give Cochran a seniority advantage over new incoming senators.[5]