Mu Ko Phetra is a marine national park in the Strait of Malacca off Thailand, covering mostly intact coastal line, open water, and about 30 islands of the southern part of Trang Province and the northern part of Satun Province. Established on 31 December 1984, it is the 49th national park and 14th marine national park of Thailand. The Thai name Phetra comes from Malay Pulau Petra (the island of Petra). The continued existence of the park is threatened by the proposed Pak Bara deepwater seaport.