Tiburon is an incorporated town in Marin County, California. It is located on the Tiburon Peninsula, which reaches south into the San Francisco Bay. The smaller city of Belvedere (formerly a separate island) occupies the south-west part of the peninsula and is contiguous with Tiburon. Tiburon is bordered by Corte Madera to the north and Mill Valley to the west, but is otherwise mostly surrounded by the Bay.