This is a list of Washington county name etymologies.

• Adams County, Washington: Adams is named for John Adams, the second president of the United States.
• Asotin County, Washington: Asotin is named for the Nez Perce name for Eel Creek .
• Benton County, Washington: Benton is named for Thomas Hart Benton, a Missouri U. S. senator.
• Chelan County, Washington: Chelan is named for a Native American word meaning deep water, probably a reference to Lake Chelan.
• Clallam County, Washington: Clallam is named for a Klallam word meaning the strong people.
• Clark County, Washington: Clark is named for William Clark, the co-captain of the Lewis and Clark Expedition.
• Columbia County, Washington: Columbia is named for the Columbia River.
• Cowlitz County, Washington: Cowlitz is named for a Cowlitz word meaning seeker (in the spiritual sense).
• Douglas County, Washington: Douglas is named for Stephen Arnold Douglas, the statesman and rival of Abraham Lincoln.
• Ferry County, Washington: Ferry is named for Elisha P. Ferry , the first governor of Washington.
• Franklin County, Washington: Franklin is named for Benjamin Franklin, the famous Founding Father, statesman, printer, and scientist.
• Garfield County, Washington: Garfield is named for James Abram Garfield, the twentieth president of the United States.
• Grant County, Washington: Grant is named for Ulysses Simpson Grant, the eighteenth president of the United States.
• Grays Harbor County, Washington: Grays Harbor is named for Grays Harbor on the county's coastline on the Pacific Ocean.
• Island County, Washington: Island is named for the fact that it consists of just two islands, Whidbey Island and Camano Island.
• Jefferson County, Washington: Jefferson is named for Thomas Jefferson, the third president of the United States.
• King County, Washington: King is named for William Rufus de Vane King, the thirteenth vice president of the United States.
• Kitsap County, Washington: Kitsap is named for Kitsap , a chief of the Suquamish tribe.
• Kittitas County, Washington: Kittitas is a Native American word of uncertain meaning.
• Klickitat County, Washington: Klickitat is named for the Klickitat tribe of the Yakama Native American Nation.
• Lewis County, Washington: Lewis is named for Meriwether Lewis, the co-captain of the Lewis and Clark Expedition.
• Lincoln County, Washington: Lincoln is named for Abraham Lincoln, the 16th president of the United States.
• Mason County, Washington: Mason is named for C. H. Mason , the first secretary of the Washington Territory.
• Okanogan County, Washington: Okanogan is named for a Salish Native American word meaning rendezvous.
• Pacific County, Washington: Pacific is named for the Pacific Ocean.
• Pend Oreille County, Washington: Pend Oreille is named for the Pend d'Oreille Native American tribe.
• Pierce County, Washington: Pierce is named for Franklin Pierce, the 14th president of the United States.
• San Juan County, Washington: San Juan is named for San Juan Island.
• Skagit County, Washington: Skagit is named for the Skagit Native American tribe.
• Skamania County, Washington: Skamania is named for a Chinookan word meaning swift water.
• Snohomish County, Washington: Snohomish is named for the Snohomish Native American tribe.
• Spokane County, Washington: Spokane is named for the Spokane Native American tribe.
• Stevens County, Washington: Stevens is named for Isaac Ingalls Stevens, the first governor of the Washington Territory.
• Thurston County, Washington: Thurston is named for Samuel Royal Thurston, Oregon Territory's first delegate to the United States Congress.
• Wahkiakum County, Washington: Wahkiakum is named for Chief Wahkiakum of the Chinook Native American tribe.
• Walla Walla County, Washington: Walla Walla is named for the Walla Walla Native American tribe.
• Whatcom County, Washington: Whatcom is named for Chief Whatcom of the Nooksack Native American tribe.
• Whitman County, Washington: Whitman is named for Marcus Whitman, a Presbyterian missionary who was killed by members of the Cayuse Native American tribe.
• Yakima County, Washington: Yakima is named for the Yakama Native American tribe.

See also

• Washington
• List of Washington counties
• County (United States)
• Lists of U.S. county name etymologies