| Election Name: | 1970 United States Senate election in California |
| Country: | California |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1964 United States Senate election in California |
| Previous Year: | 1964 |
| Next Election: | 1976 United States Senate election in California |
| Next Year: | 1976 |
| Election Date: | November 3, 1970 |
| Image1: | Sen John V Tunney.jpg |
| Nominee1: | John V. Tunney |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 3,496,558 |
| Percentage1: | 53.86% |
| Nominee2: | George Murphy |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 2,877,617 |
| Percentage2: | 44.33% |
| Map Size: | 300px |
| U.S. Senator | |
| Before Election: | George Murphy |
| Before Party: | Republican Party (United States) |
| After Election: | John V. Tunney |
| After Party: | Democratic Party (United States) |
The 1970 United States Senate election in California was held on November 3, 1970.
Incumbent Republican Senator George Murphy lost re-election to a second term to Democratic Congressman John V. Tunney. This election was the first since 1860 in which California sent two Democrats to the U.S. Senate.