Ko Phi Phi Leh (or Ko Phi Phi Ley) is an island of the Phi Phi archipelago, in the Andaman Sea. It belongs to the Krabi province of Thailand.
Ko Phi Phi Leh is the second largest island of the archipelago, the largest one being Ko Phi Phi Don. The island consists of a ring of steep limestone hills surrounding a shallow bay, the Mahya Bay.

Mahya Bay (or Maya Bay) is popular for diving, and has become even more popular after the 2000 movie The Beach was filmed there. According to the Lonely Planet's Thailand guidebook, the 2004 tsunami dramatically improved the look of Maya Bay. This was due to the fact that the high waves had cleaned up the beach and removed all the landscaping the Fox production team had added.

Controversy arose during the making of the film The Beach due to 20th Century Fox bulldozing and rescaping of the natural beach setting of Ko Phi Phi Leh to make it more "paradise-like". The production altered some sand dunes and cleared some coconut trees and grass to widen the beach. Fox set aside a fund to reconstruct and return the beach to its natural state, however lawsuits were filed as many believed the damage to the ecosystem is permanent and restoration attempts failed.

The lawsuits dragged on for years. In 2006, Thailand's Supreme Court upheld an appeal court ruling that the filming had harmed the environment and ordered that damage assessments be made. Defendants in the case included 20th Century Fox and some Thai government officials.

Prior to 2004 the island had avoided development. However, it is now a part of Phi Phi National Park and has since begun to see the beginnings of development and some clearing of natural plant life. There are current plans to build bungalows on the island and as of 2004 an entry-fee of 40 Baht has been charged; as of February 2007 the charge for private visitors has been raised to Bt200 per person. There are now permanent basic facilities on the island - toilets, a snack bar and camping sites.