Basilan Island is an island of the Philippines, it belongs to Basilan Province with its capital Isabela City.
Basilan is geographically located between latitude 6°15' and 7°00' longitude 121°15' and 122°30'.
Basilan is one of a system of 7,107 islands that make up the Philippine archipelago. Regionally, Basilan is the biggest and northernmost island of the Sulu Archipelago between the Philippine island of Mindanao and Borneo which includes about 400 islands. The island chain is one of two partial land bridges to Borneo and is an important migration route for birds. Basilan Strait, about 17 nautical miles (31 km) at its narrowest point, separates Basilan Island from the mainland of Mindanao and the port city of Zamboanga.
The island is washed by the Basilan Strait from the North, the Sulu Sea from the Northwest and West, the Moro Gulf from the Northeast, and the Celebes Sea from the South, Southeast and East.