| Election Name: | 1966 United States Senate election in Idaho |
| Country: | Idaho |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1962 United States Senate special election in Idaho |
| Previous Year: | 1962 (special) |
| Next Election: | 1972 United States Senate election in Idaho |
| Next Year: | 1972 |
| Election Date: | November 8, 1966 |
| Image1: | Lenjordan.jpg |
| Nominee1: | Len Jordan |
| Party1: | Republican Party (US) |
| Popular Vote1: | 139,819 |
| Percentage1: | 55.38% |
| Party2: | Democratic Party (US) |
| Popular Vote2: | 112,637 |
| Percentage2: | 44.62% |
| Map Size: | 250px |
| U.S. Senator | |
| Before Party: | Republican Party (US) |
| After Party: | Republican Party (US) |
The 1966 United States Senate election in Idaho took place on November 8, 1966. Incumbent Republican Senator Leonard B. Jordan was re-elected to a second term in office over Democratic U.S. Representative Ralph R. Harding.