Khao Tha Phet (Thai: เขาท่าเพชร) is a hill near the city of Surat Thani in Southern Thailand. It is located in Makham Tia Subdistrict, Surat Thani City. The hill has an altitude of about 210 m (690 ft) above sea level and offers a good view over the city.

On top of the hill is the Si Surat stupa (also known by its common name Phra That Khao Tha Phet), a Srivijavan-style stupa built in 1957. The stupa contains a Buddha relic donated by India. Next to the stupa is a Sweet Shorea tree (Shorea roxburghii) planted by King Bhumibol Adulyadej.

Due to its height over the city, several TV and radio transmitters are located on the hill. A portion of the hill, around 4.65 km² (1.86 sq. miles) in size, was designated a protected non-hunting area on July 26, 1977.

• List of mountains in Thailand

• National Park, Wildlife and Plant Conservation Department (Thai)
• Royal Gazette Issue 94 chapter 68 of June 26 1977 (Thai)