Ko Pha-ngan (Thai: เกาะพะงัน, RTGS: Ko Pha-ngan, pronounced [kɔ̀ʔ pʰā.ŋān]) is an island in the Gulf of Thailand in Surat Thani Province of southern Thailand. Ko Pha-ngan has two sister islands: the larger Ko Samui to the south and the smaller Ko Tao to the north.
Estimated perimeter: 40 km (25 mi) (estimated 10 hr average walking time)
From mainland: about 55 km (34 mi)
From Ko Samui: about 15 km (9.3 mi)
From Ko Tao: about 35 km (22 mi)
Main town: Thong Sala
Highest Point: Khao Ra, 635 m (2,083 ft)
