High Quality Content by WIKIPEDIA articles! Whidbey Island (historical spelling Whidby) is the largest of nine islands located in Island County, Washington, in the United States. Whidbey is about 30 miles (48 km) north of Seattle, and lies between the Olympic Peninsula and the I-5 corridor of western Washington. The island forms the northern boundary of Puget Sound. It is home to Naval Air Station Whidbey Island.