| Election Name: | 1918 United States Senate election in Wyoming |
| Country: | Wyoming |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1913 United States Senate election in Wyoming |
| Previous Year: | 1913 |
| Next Election: | 1924 United States Senate election in Wyoming |
| Next Year: | 1924 |
| Election Date: | November 5, 1918 |
| Image1: | Francis E. Warren.jpg |
| Nominee1: | Francis E. Warren |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 23,975 |
| Percentage1: | 57.77% |
| Nominee2: | John E. Osborne |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 17,528 |
| Percentage2: | 42.23% |
| Map Size: | 250px |
| U.S. Senator | |
| Before Election: | Francis E. Warren |
| Before Party: | Republican Party (United States) |
| After Election: | Francis E. Warren |
| After Party: | Republican Party (United States) |
The 1918 United States Senate election in Wyoming took place on November 5, 1918. Incumbent Republican Senator Francis E. Warren ran for re-election to his fifth consecutive term in the Senate, in his first popular election. He was opposed by former Governor John E. Osborne, the Democratic nominee, who had until recently served as the U.S. Assistant Secretary of State. Owing in part to Warren's long record of service, and also to the strong Republican performance throughout the country in the 1918 elections, Warren defeated Osborne by a wide margin.