Woodinville, Washington (Wikipedia) Woodinville is a city in King County, Washington, United States. It is a part of the Seattle metropolitan area. There is also a much larger population with Woodinville mailing addresses in adjacent unincorporated areas of King (Cottage Lake) and Snohomish (Maltby) counties. Woodinville has waterfront parks on the Sammamish River, sweeping winery and brewery grounds, and densely wooded areas.