| Election Name: | 1976 United States Senate election in California |
| Country: | California |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1970 United States Senate election in California |
| Previous Year: | 1970 |
| Next Election: | 1982 United States Senate election in California |
| Next Year: | 1982 |
| Election Date: | November 2, 1976 |
| Image1: | File:Samuel Ichiye Hayakawa, 1976 (cropped).jpg |
| Nominee1: | S. I. Hayakawa |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 3,748,973 |
| Percentage1: | 50.12% |
| Nominee2: | John V. Tunney |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 3,502,862 |
| Percentage2: | 46.89% |
| Map Size: | 300px |
| U.S. Senator | |
| Before Election: | John V. Tunney |
| Before Party: | Democratic Party (United States) |
| After Election: | S. I. Hayakawa |
| After Party: | Republican Party (United States) |
The 1976 United States Senate election in California took place on November 2, 1976. Incumbent Democratic U.S. Senator John V. Tunney ran for re-election to a second term, but was defeated by Republican S. I. Hayakawa. As of 2023, this is the last time an incumbent Democratic Senator from California lost re-election.
Primary elections were held on June 8. Tunney survived a challenge from anti-war activist Tom Hayden, the husband of Jane Fonda. Hayakawa, a novice campaigner, won a surprise victory over seasoned political figures Robert H. Finch, Alphonzo Bell Jr., and John L. Harmer.