Sisowath Watchayavong (Khmer: ស៊ីសុវត្ថិ វឌ្ឍឆាយាវង្ស; 13 September 1891^[1] – 30 January 1972) was a Cambodian politician who served as the Prime Minister of Cambodia from 1947 to 1948. He was a grandson of King Sisowath.

He was appointed to the High Council of the Kingdom in 1967. He had at least 25 children.^{[1][page needed]}