2018 United States Senate election in Washington

The 2018 United States Senate election in Washington took place on November 6, 2018, to elect a member of the United States Senate to represent the State of Washington. Incumbent Democrat Maria Cantwell won election to a fourth term over television news journalist Susan Hutchison, a Republican.

Candidates
The primary election featured 30 candidates.

Declared

 * Maria Cantwell, incumbent senator
 * Don L. Rivers
 * Clint Tannehill
 * George H. Kalberer
 * Mohammad Said

Declared

 * Joey Gibson, activist and founder of Patriot Prayer
 * Goodspaceguy, perennial candidate
 * Susan Hutchison, former chair of the Washington State Republican Party
 * Rocky De La Fuente, businessman and former presidential candidate
 * Tim Owen
 * Matthew D. Heines
 * Art Coday
 * John Orlinski
 * Keith Swank
 * RC Smith
 * Dave Bryant
 * Matt Hawkins
 * Glen Stockwell

Withdrawn

 * Ron Higgins (withdrew May 19, 2018 )

Declared

 * Jennifer "GiGi" Ferguson
 * Thor Amundson
 * Dave Strider
 * Charlie R Jackson
 * Jon Butler

Write-in

 * Clay Johnson, activist

Minor parties
In Washington, primary candidates may declare a preference for any party, and their party preference does not imply that the candidate is nominated or endorsed by the party. Candidates may also declare a preference for new or single-candidate parties.

Declared

 * Mike Luke (Libertarian Party)
 * Brad Chase (FDFR Party), communications strategist
 * Sam Wright (The Human Rights Party)
 * Alex Tsimerman (StandupAmerica)
 * Steve Hoffman (Freedom Socialist Party), union organizer
 * James Robert "Jimmie" Deal (Green Party)

Polling

 * Maria Cantwell vs. Rob McKenna

Counties that flipped from Democratic to Republican

 * Cowlitz (largest city: Longview)
 * Grays Harbor (largest city: Aberdeen)
 * Klickitat (Largest city: Goldendale)
 * Mason (largest city: Shelton)
 * Skamania (Largest city: Carson)
 * Yakima (Largest city: Yakima)
 * Wahkiakum (Largest city: Puget Island)

Counties that flipped from Republican to Democratic

 * Whitman (Largest city: Pullman)

By congressional district
Cantwell won 7 of 10 congressional districts.