The 2010 United States Senate election in Washington was held on November 2, 2010 alongside other elections to the United States Senate in other states as well as elections to the United States House of Representatives and various state and local elections. Incumbent Democratic U.S. Senator Patty Murray won re-election to a fourth term by a margin of 52.1% – 47.4% over Republican Dino Rossi, who had twice run for governor in 2004 and 2008. As of 2022, this was the last U.S. Senate election in Washington in which the margin of victory was within single digits.