| Election Name: | 1863 United States Senate election in California |
| Type: | presidential |
| Ongoing: | no |
| Flag Image: | First Bear Flag of California (1846).svgborder |
| Previous Election: | 1860 United States Senate special election in California |
| Previous Year: | 1860 (special) |
| Next Election: | 1867 United States Senate election in California |
| Next Year: | 1867 |
| Election Date: | February 10, 1863 |
| Votes For Election: | Majority vote of both houses needed to win |
| 1Blank: | Joint session |
| 2Blank: | Percentage |
| Image1: | John Conness (3x4) a.jpg |
| Nominee1: | John Conness |
| Party1: | National Union Party (United States) |
| 1Data1: | 98 |
| 2Data1: | 85.96% |
| Nominee2: | Benjamin Shurtleff |
| Party2: | Democratic Party (United States) |
| 1Data2: | 15 |
| 2Data2: | 13.16% |
| Senator | |
| Before Election: | Milton Latham |
| Before Party: | Lecompton Democrat |
| After Election: | John Conness |
| After Party: | National Union Party (United States) |
The 1863 United States Senate election in California was held on February 10, 1863, by the California State Legislature to elect a U.S. Senator (Class 1) to represent the State of California in the United States Senate. In a special joint session, former Democratic State Assemblyman John Conness was elected over fellow Democratic State Senator Benjamin Shurtleff.[1] Conness was supported by the Union Party, while Shurtleff (despite being a unionist himself)[2] was supported by the Southern Democrats.[3]