Ko Sarai
file:Ao_Ta_Lo_Woo_Pier,_Ko_Tarutao_-_Tarutao_National_Park_.jpg|thumb|Ao Talo Wao, bight and pier in Ko Sarai, Ko Tarutao
Ko Sarai is a subdistrict in Mueang Satun District, Satun Province, Thailand. It is composed of 3 island groups, totaling 243 km2, and has a population of 5077 as of 2012.
- The biggest village is Ban Ko Sarai, on the island with the same name.
- The population relies on fishing, agriculture and tourism.
- Amongst the attractions, Ko Tarutao, Ko Lipe, Ko Adang.