Port Madison, sometimes called Port Madison Bay, is a deep water bay located on the west shore of Puget Sound in western Washington. It is bounded on the north by Indianola, on the west by Suquamish, and on the south by Bainbridge Island. Port Madison connects to Bainbridge Island via the Agate Pass Bridge to the southwest. Two small bays open off Port Madison: Miller Bay to the northwest, and another small bay to the south which, confusingly, is also called Port Madison Bay.