Mukilteo, Washington. Mukilteo (/ˌmʌkəlˈtiːoʊ/ MUK-əl-TEE-oh), which means good camping ground, is a waterfront city in Snohomish County, Washington, United States. The population was 20,254 at the 2010 census. It is on the shore of the Puget Sound, and is the site of a Washington State Ferries terminal linking it to Clinton, on Whidbey Island.