| Election Name: | 1964 United States Senate election in New Mexico |
| Country: | New Mexico |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1958 United States Senate election in New Mexico |
| Previous Year: | 1958 |
| Next Election: | 1970 United States Senate election in New Mexico |
| Next Year: | 1970 |
| Election Date: | November 3, 1964 |
| Image1: | Joseph_Montoya.jpg |
| Nominee1: | Joseph Montoya |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 178,209 |
| Percentage1: | 54.70% |
| Nominee2: | Edwin L. Mechem |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 147,562 |
| Percentage2: | 45.30% |
| Map Size: | 230px |
| U.S. Senator | |
| Before Election: | Edwin L. Mechem |
| Before Party: | Republican Party (United States) |
| After Election: | Joseph Montoya |
| After Party: | Democratic Party (United States) |
The 1964 United States Senate election in New Mexico took place on November 3, 1964. Incumbent Republican U.S. Senator Edwin L. Mechem, who appointed himself to the office after the death of his predecessor, sought election to a full term. However, he was defeated by Democrat Joseph Montoya. Mechem was an ally of Arizona Senator and candidate for president Barry Goldwater who lost in a landslide on the same ballot. This and his very conservative voting record were widely seen as reasons for his loss.