Ko Adang (Thai: เกาะอาดัง, pronounced [kɔ̀ʔ ʔāːdāŋ]) is the second biggest island within Tarutao National Marine Park, in Thailand, very close to Ko Lipe island.

The highest point on the island is 690 m.[1][2] Adang is surrounded by only few sandy beaches, but the offshore coral reef is abundant.

The island is very quiet and undeveloped, thanks to being part of Tarutao National Park.

On the southern tip (closest to Ko Lipe) there are camping facilities, as well as bungalows, all belonging to the national park.

Long-tail boats can be hired to get to other sights on and around Ko Adang, including a black sand beach to the north of the island.