Chumphon (Thai: จังหวัดชุมพร; English: Chumphon Province), also known as "Chumphon", is a province in southern Thailand, located in the narrowest part of the Malay Peninsula. It is bordered by Myanmar to the west, Thailand's Prachuap Khiri Khan and Surat Thani to the north and south respectively, Ranong to the southwest, and the Gulf of Thailand (formerly known as the Gulf of Siam) to the east.