| Election Name: | 1966 United States Senate election in Minnesota |
| Country: | Minnesota |
| Flag Year: | 1957 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1960 United States Senate election in Minnesota |
| Previous Year: | 1960 |
| Next Election: | 1972 United States Senate election in Minnesota |
| Next Year: | 1972 |
| Election Date: | November 8, 1966 |
| Image1: | Mondale as Senator.jpg |
| Nominee1: | Walter Mondale |
| Party1: | Minnesota Democratic–Farmer–Labor Party |
| Popular Vote1: | 685,840 |
| Percentage1: | 53.94% |
| Nominee2: | Robert Forsythe |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 574,868 |
| Percentage2: | 45.21% |
| Map Size: | 280px |
| U.S. Senator | |
| Before Election: | Walter Mondale |
| Before Party: | Minnesota Democratic–Farmer–Labor Party |
| After Election: | Walter Mondale |
| After Party: | Minnesota Democratic–Farmer–Labor Party |
The 1966 United States Senate election in Minnesota took place on November 8, 1966. Incumbent Democratic U.S. Senator Walter Mondale, who had originally been appointed in 1964 to replace Hubert Humphrey after Humphrey was elected Vice President of the United States, defeated Republican challenger Robert A. Forsythe, to win a full term.