Mok Mareth (Khmer: ម៉ុក ម៉ារ៉េត; born 20 January 1944) is a Cambodian politician and former Minister of the Environment.

He was born in Rumchang, Samraŏng District, Takéo Province, Cambodia.

Prior to these positions he served as vice president of the Phnom Penh party committee (1981–1989).

A natural scientist by training, Mareth earned a bachelor's degree in agronomy and fisheries engineering from the University of Agronomy, Phnom Penh, Cambodia in 1970 and his PhD in animal and aquatic biology from Paul Sabatier University, in Toulouse, France in 1974.

After completing his doctoral work, he was a biological researcher at ORSTROM in France (1974–1976).