Khao Sam Roi Yot National Park (Thai: อุทยานแห่งชาติเขาสามร้อยยอด, RTGS: Utthayan Haeng Chat Khao Sam Roi Yot, pronounced [ʔùt.tʰā.jāːn hɛ̀ŋ tɕʰâːt kʰǎw sǎːm rɔ́ːj jɔ̂ːt]) is a marine national park in Kui Buri District, Prachuap Khiri Khan Province, Thailand.

Hat Laem Sala is 17 km from park headquarters and can be reached from the village Ban Pu either by boat or by climbing up and down over a hill for nearly 30 minutes.

[4] Phraya Nakhon Cave (ถ้ำพระยานคร) is about 500 meters (1,600 ft) from Laem Sala Beach, approximately 17 kilometers (11 mi) north of park headquarters.

Klong Khao Daeng is a 4-kilometer-long (2.5 mi) stream running deep into mangrove forests at one end and at its mouth freshwater and seawater collide.

Wildlife found in the mangroves includes pla teen (mudskippers), pu kam dab (fiddler crabs), ling samae (the crab-eating macaque), collared kingfisher (nok kin pieo), snapping shrimp (kung deed khan), mud creeper (hoi khika), and oysters (hoi nangrom).

[4][7] Rare animals in the park include the mainland serow (Nemorhaedus sumatraensis), dusky langurs (Trachypithecus obscurus), fishing cats (Prionailurus viverrinus) (Thai: เสือปลา; RTGS: suea pla),[5] as well as many bird species.

[8] Khao Sam Roi Yot was probably where King Mongkut hosted European guests on 18 August 1868 to observe a total solar eclipse.

According to archeologist Kannika Premjai, paintings describe humanlike figures with accessories on their bodies, hunting scenes with bow and arrow.

[11] In October 2020, more rock art was discovered in unmapped caves in Sam Roi Yot National Park, dating back to between 2,000 and 3,000 years ago.