Koh wai  is a small island in Ko Chang Archipelago, Trat Province, eastern Thailand.  The island has nice views over the other islands in the vicinity.

Koh  Wai Island has an irregular shape and is 3 km long and 1 km wide at the widest point. The east part of the island is encircled by coral reef and has sand beaches while the west part is more rugged and hilly, and serves as a nesting ground for birds. The interior is covered by forest jungle. There are four bungalow operations on the island and daily boat connections to Ko Chang, Ko Mak, and the mainland, during the season.