| Election Name: | 1946 United States Senate election in Delaware |
| Country: | Delaware |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1940 United States Senate election in Delaware |
| Previous Year: | 1940 |
| Next Election: | 1952 United States Senate election in Delaware |
| Next Year: | 1952 |
| Election Date: | November 5, 1946 |
| Nominee1: | John J. Williams |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 62,603 |
| Percentage1: | 55.15% |
| Nominee2: | James M. Tunnell |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 50,910 |
| Percentage2: | 44.85% |
| Map Size: | 200px |
| U.S. Senator | |
| Before Election: | James M. Tunnell |
| Before Party: | Democratic Party (United States) |
| After Election: | John J. Williams |
| After Party: | Republican Party (United States) |
The 1946 United States Senate election in Delaware took place on November 5, 1946. Incumbent Democratic U.S. Senator James M. Tunnell ran for re-election to a second term in office, but was defeated in a landslide by Republican John J. Williams, a businessman and member of the Millsboro Town Council.