Chumphon is one of the southern provinces (changwat) of Thailand, in the coast of the Gulf of Thailand.  The neighboring provinces are (north to the right) Prachuap Khiri Khan, Gentlemen of Surat and Ranong.  Al western also borders Myanmar. 

Chumphon is located in the Isthmus of Kra, the landbridge narrow that connects the Malayan Peninsula with the continent of Thailand.  Al western are the hills of the mountain range of Phuket and their northern continuation, the chain of Tenasserim, while the east is the flattest land in the shelter al Gulf of Thailand.  The main river is the Lang Suan, that originates in the district of Phato.