Guernsey, island, 25 sq mi (65 sq km), in the English Channel, second largest of the Channel Islands. Guernsey bailiwick (2005 est. pop. 65,000) includes Alderney, Sark, Herm, Brechou, Jethou, and smaller islands. Guernsey has a low beach in the north and rocky cliffs along the south shore. The shipping and distribution center and chief town is Saint Peter Port. Exports include dairy products, fruits, flowers, vegetables, and Guernsey cattle. It is a tourist site.