| Election Name: | 1928 United States Senate election in Delaware |
| Country: | Delaware |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1922 United States Senate election in Delaware |
| Previous Year: | 1922 |
| Next Election: | 1934 United States Senate election in Delaware |
| Next Year: | 1934 |
| Election Date: | November 6, 1928 |
| Nominee1: | John G. Townsend Jr. |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 63,725 |
| Percentage1: | 60.95% |
| Nominee2: | Thomas F. Bayard Jr. |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 40,828 |
| Percentage2: | 39.05% |
| U.S. Senator | |
| Before Election: | Thomas F. Bayard Jr. |
| Before Party: | Democratic Party (United States) |
| After Election: | John G. Townsend Jr. |
| After Party: | Republican Party (United States) |
The 1928 United States Senate election in Delaware took place on November 6, 1928. Incumbent Republican U.S. Senator Thomas F. Bayard Jr. ran for a third term in office, but was defeated by former Republican Governor John G. Townsend Jr. in a landslide.