| Election Name: | 1966 United States Senate election in Maine |
| Country: | Maine |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1960 United States Senate election in Maine |
| Previous Year: | 1960 |
| Next Election: | 1972 United States Senate election in Maine |
| Next Year: | 1972 |
| Election Date: | November 8, 1966 |
| Nominee1: | Margaret Chase Smith |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 188,291 |
| Percentage1: | 58.93% |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 131,136 |
| Percentage2: | 41.04% |
| Map Size: | 250px |
| U.S. senator | |
| Before Party: | Republican Party (US) |
| After Party: | Republican Party (US) |
The 1966 United States Senate election in Maine was held on November 8, 1966. Incumbent Republican U.S. Senator Margaret Chase Smith was re-elected to a fourth term over Democratic State Senator Elmer H. Violette.
Senator Smith was unopposed for renomination