2005 King County Executive election

The 2005 King County Executive election was held on November 8, 2005. The election, which was the first to take place after Washington's blanket primary was invalidated, used separate primaries. Incumbent Democratic County Executive Ron Sims, who unsuccessfully sought the Democratic nomination for Governor in 2004, ran for re-election to a third term. He was challenged by two lesser-known candidates in the Democratic primary, and won by a wide margin, but the race was closer than expected.

In the general election, Sims was challenged by County Councilman David Irons, the Republican nominee. Irons attacked Sims for his "lack of experience in knowing how to manage and lead," citing alleged mismanagement of the county elections office during the 2004 gubernatorial election. Though Sims's campaign acknowledged that seeking a third term was a challenge due to voter fatigue, and Irons was seen as a strong candidate, Sims defeated him in a landslide, winning 56 percent of the vote to Irons's 40 percent.