1857 United States Senate special election in California

{{Infobox election

| election_name = 1857 United States Senate special election in California

| type = presidential

| ongoing = no

| flag_image = First Bear Flag of California (1846).svg{{!}}border

| 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%

| image2 = Henry A. Crabb 3x4.jpg

| 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%

| title = Senator

| before_election = None
(Legislature failed to elect)

| before_party =

| 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.{{cite news |author= |date=15 January 1857 |title=California Legislature |url=https://cdnc.ucr.edu/?a=d&d=SRP18570115.2.6&srpos=1&e=------185-en--20--1--txt-txIN-gwin+senate+assembly----1857--- |work=San Joaquin Republican |location=Stockton |access-date=1 November 2024}}