Whidbey Island (historical spellings Whidby, Whitbey, or Whitby) is the largest of the islands composing Island County, Washington, in the United States. (The other large island is Camano Island, east of Whidbey.) Whidbey is about 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.