| Election Name: | Washington State Senate elections, 2010 |
| Country: | Washington |
| Type: | legislative |
| Ongoing: | no |
| Previous Election: | 2008 Washington State Senate election |
| Previous Year: | 2008 |
| Next Election: | 2012 Washington State Senate election |
| Next Year: | 2012 |
| Seats For Election: | 25 seats of the Washington State Senate |
| Majority Seats: | 25 |
| Election Date: | November 2, 2010 |
| Image1: | File:3x4.svg |
| Leader1: | Rosa Franklin (retired) |
| Party1: | Democratic |
| Leaders Seat1: | 29th-Tacoma |
| Last Election1: | 31 |
| Seats1: | 27 |
| Seat Change1: | 4 |
| Leader2: | Mike Hewitt |
| Party2: | Republican |
| Leaders Seat2: | 16th-Walla Walla |
| Last Election2: | 18 |
| Seats2: | 22 |
| Seat Change2: | 4 |
| Map Size: | 350px |
| President pro tempore | |
| Before Election: | Rosa Franklin |
| Before Party: | Democratic |
| After Election: | Margarita Prentice |
| After Party: | Democratic |
The Washington State Senate elections were held on November 2, 2010,[1] in which about half of the state's 49 legislative districts choose a state senator for a four-year term to the Washington State Senate. The other half of state senators are chosen in the next biennial election, so that about half of the senators, along with all the members of the Washington State House of Representatives, are elected every two years.
24 seats were regularly scheduled to be up this cycle, along with 1 additional seat holding a special election to fill an unexpired term: the 28th district, held by appointed Senator Steve Litzow, whose former incumbent Fred Jarrett vacated the seat.
| State Senate District | Incumbent | Party | Elected Senator | Party | |||
|---|---|---|---|---|---|---|---|
| 6th | Chris Marr | Dem | Michael Baumgartner | Rep | |||
| 7th | Bob Morton | Rep | Bob Morton | Rep | |||
| 8th | Jerome Delvin | Rep | Jerome Delvin | Rep | |||
| 13th | Janéa Holmquist Newbry | Rep | Janéa Holmquist Newbry | Rep | |||
| 15th | Jim Honeyford | Rep | Jim Honeyford | Rep | |||
| 21st | Paull Shin | Dem | Paull Shin | Dem | |||
| 26th | Derek Kilmer | Dem | Derek Kilmer | Dem | |||
| 29th | Rosa Franklin | Dem | Steve Conway | Dem | |||
| 30th | Tracey Eide | Dem | Tracey Eide | Dem | |||
| 31st | Pam Roach | Rep | Pam Roach | Rep | |||
| 32nd | Darlene Fairley | Dem | Maralyn Chase | Dem | |||
| 33rd | Karen Keiser | Dem | Karen Keiser | Dem | |||
| 34th | Joe McDermott | Dem | Sharon K. Nelson | Dem | |||
| 35th | Tim Sheldon | Dem | Tim Sheldon | Dem | |||
| 36th | Jeanne Kohl-Welles | Dem | Jeanne Kohl-Welles | Dem | |||
| 37th | Adam Kline | Dem | Adam Kline | Dem | |||
| 38th | Jean Berkey | Dem | Nick Harper | Dem | |||
| 41st | Randy Gordon | Dem | Steve Litzow | Rep | |||
| 42nd | Dale Brandland | Rep | Doug Ericksen | Rep | |||
| 43rd | Ed Murray | Dem | Ed Murray | Dem | |||
| 44th | Steve Hobbs | Dem | Steve Hobbs | Dem | |||
| 45th | Eric Oemig | Dem | Andy Hill | Rep | |||
| 46th | Ken Jacobson | Dem | Scott White | Dem | |||
| 47th | Claudia Kauffman | Dem | Joe Fain | Rep | |||
| 48th | Rodney Tom | Dem | Rodney Tom | Dem | |||