| Election Name: | 1857 United States Senate special election in California |
| Type: | presidential |
| Ongoing: | no |
| Flag Image: | First Bear Flag of California (1846).svgborder |
| Previous Election: | 1849 United States Senate elections in California |
| Previous Year: | 1849 |
| Next Election: | 1861 United States Senate election in California |
| Next Year: | 1861 |
| Election Date: | January 13, 1857 |
| Votes For Election: | Majority vote of both houses needed to win |
| 1Blank: | Joint session |
| 2Blank: | Percentage |
| Image1: | Mr. Given - NARA - 528394 3x4.jpg |
| Nominee1: | William M. Gwin |
| Party1: | Democratic Party (United States) |
| 1Data1: | 82 |
| 2Data1: | 72.57% |
| Nominee2: | Henry A. Crabb |
| Party2: | Know Nothing |
| 1Data2: | 17 |
| 2Data2: | 15.04% |
| Image3: | A. A. Sargent 3x4.jpg |
| Nominee3: | Aaron A. Sargent |
| Party3: | Republican Party (United States) |
| 1Data3: | 11 |
| 2Data3: | 9.73% |
| Senator | |
| Before Election: | None (Legislature failed to elect) |
| After Election: | William M. Gwin |
| After Party: | Democratic Party (United States) |
The 1857 United States Senate special election in California was held on January 13, 1857, by the California State Legislature to elect a U.S. Senator (Class 3) to represent the State of California in the United States Senate. Legislators had previously attempted to elect a Senator in 1855, but could not reach a majority for a single candidate. In a special joint session, former Democratic Senator William M. Gwin was re-elected over Know Nothing State Senator Henry A. Crabb and Republican Nevada County District Attorney Aaron A. Sargent.[1]