Koh Tao is an island in Thailand located near the eastern shore of the Gulf of Thailand. It covers an area of about 21 km² and in Thai Koh Tao means Turtle Island. Administratively it forms a tambon within the district (Amphoe) Koh Phangan of Surat Thani Province. As of 2006 its official population number is 1382. The main settlement is Ban Mae Hat.
The economy of the island is almost exclusively centered around tourism, especially scuba diving with divers flocking to the island from all over the world.
Koh Tao was named by its first settlers for the island's turtle-like geographic shape. Coincidentally, the island is an important breeding ground for Hawksbill turtles and Green turtles. Development of tourism has negatively impacted the health of these grounds but a breeding program organised in 2004 by the Royal Thai Navy and KT-DOC, a coalition of local scuba diving centres has reintroduced hundreds of juvenile turtles to the island's ecosystem.
There are few roads on the island and transport to Koh Tao is via a high speed catamaran service, several ferry boats and a night boat from Surat Thani.
The island is well known for scuba diving and snorkeling, and also offers some hiking. The most popular place for tourists is Sairee on the West coast, which has a white sandy beach of 1.7 km interrupted only by a few huge boulders and a scattering of medium budget resorts and restaurants. A multitude of beautiful granite boulders, which nestle both in the forests and on the beaches of Ko Tao, attract a growing number of climbers who visit each year to enjoy the adventurous aspect of their sport.
Koh Tao is less developed than Koh Samui and Koh Phangan, but has become increasingly popular especially with the mid-20's backpacker crowd in search of relatively inexpensive scuba diving certification.
Koh Tao has about 170 resorts offering accommodation and there are approximately 50 bars and clubs. Most of the resorts are still bungalow-style, not hotel/resort style. There is a trend to more upmarket resorts which do not concentrate singularly on diving.