The Similan Islands is a group of islands in the Andaman Sea off the coast of Phang Nga Province, southern Thailand. It is a national park which was established in 1982.
Similan Islands National Park was established after the one-year exploration by the Foresty department. The park is the archipelago consisting of nine islands which are Ko Bon, Ko Bayu, Ko Similan, Ko Payu, Ko Miang (two adjoining islands), Ko Payan, Ko Payang, and Ko Huyong. Recently, the park was expanded to included two remoted islands which are Ko Bon and Ko Tachai. The Similans are situated 70 kilometres from Phang Nga town. "Similan" is a Yawi word which means "nine". Similan is one of the most famous diving sites in Thailand.