Than Kyun or Davis Island is an island at the southern end of the Mergui Archipelago, Burma. It is the largest and highest island of the Alladin Islands, a scattered cluster of islands extending to the W and SSW of Zadetkyi Island. This densely wooded island has two main peaks, each with a height of around 450 m. The island has a roughly round shape with a diameter of about 6 km. Off its eastern shore rises a 5.5 m high rock surrounded by a reef. Than Kyun lies 4.5 km west of the southern end of Zadetkyi Island.