The "island" in Island County is Whidbey Island, the longest island in Puget Sound. The other inhabited island in the county is Camano Island, between Whidbey Island and the mainland. Camano is connected to the mainland by Highway 532 at Stanwood.
Whidbey Island has transportation links to the mainland at both ends. Whidbey is also accessible from the Olympic and Kitsap Peninsulas. The north end is connected by the bridge at Deception Pass. Ferry service joins Clinton at the south end of the island with Mukilteo on the mainland. Ferry service joins Keystone Landing (about three mile from Coupeville) at the center of Whidbey, to Port Townsend on the Olympic Peninsula. The three incorporated communities on Whidbey Island are Oak Harbor (the largest city), and the two very small towns of Coupeville (county seat and oldest town) and Langley. Camano Island is a "community" but is entirely rural.