| Election Name: | 2012 California State Senate election |
| Country: | California |
| Type: | legislative |
| Ongoing: | no |
| Previous Election: | 2010 California State Senate election |
| Previous Year: | 2010 |
| Next Election: | 2014 California State Senate election |
| Next Year: | 2014 |
| Seats For Election: | 20 seats from odd-numbered districts in the California State Senate |
| Majority Seats: | 21 |
| Leader1: | Darrell Steinberg |
| Party1: | California Democratic Party |
| Leaders Seat1: | 6th–Sacramento |
| Seats Before1: | 25 |
| Seats After1: | 29 |
| Seat Change1: | 4 |
| Popular Vote1: | 4,035,256 |
| Percentage1: | 62.61% |
| Leader2: | Bob Huff |
| Party2: | California Republican Party |
| Leaders Seat2: | 29th–Diamond Bar |
| Seats Before2: | 15 |
| Seats After2: | 11 |
| Seat Change2: | 4 |
| Popular Vote2: | 2,321,286 |
| Percentage2: | 36.02% |
| Map Size: | 450px |
| President pro tempore | |
| Posttitle: | President pro tempore-designate |
| Before Election: | Darrell Steinberg |
| Before Party: | California Democratic Party |
| After Election: | Darrell Steinberg |
| After Party: | California Democratic Party |
The 2012 California State Senate election was held on November 6, 2012, with the primary election on June 5, 2012. Voters in the 20 odd-numbered districts of the California State Senate voted for their representatives. Other elections were also held on November 6. The same year, voters also passed Proposition 28 that relaxed term limits on legislators in both chambers.[1]
| California State Senate elections, 2012 Primary election — June 5, 2012 | |||||||
|---|---|---|---|---|---|---|---|
| Party | Votes | Percentage | Candidates | Advancing to general | Seats contesting | ||
| Democratic | 1,534,788 | 59.34% | 28 | 22 | 20 | ||
| Republican | 1,015,668 | 39.27% | 20 | 16 | 16 | ||
| Libertarian | 23,098 | 0.89% | 2 | 0 | 0 | ||
| No party preference | 11,923 | 0.46% | 1 | 0 | 0 | ||
| Peace and Freedom | 788 | 0.03% | 2 | 2 | 2 | ||
| Totals | 2,586,265 | 100.00% | 53 | 40 | — | ||
| California State Senate elections, 2012 General election — November 6, 2012 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Party | Votes | Percentage | Not up | Contested | Before | After | +/– | ||
| Democratic | 4,035,256 | 62.61% | 14 | 11 | 25 | 29 | 4 | ||
| Republican | 2,321,286 | 36.02% | 6 | 9 | 15 | 11 | 4 | ||
| Peace and Freedom | 88,658 | 1.38% | 0 | 0 | 0 | 0 | |||
| Totals | 6,445,200 | 100.00% | 20 | 20 | 40 | 40 | — | ||
| 29 | 11 | ||
| Democratic | Republican | ||
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