| Sisowath Monireth, Crown Prince of Cambodia | |
| Office: | Chairman of the Regency Council |
| Primeminister: | Norodom Sihanouk Pho Proeung |
| Term Label: | Acting |
| Term Start: | 6 April 1960 |
| Term End: | 13 June 1960 |
| Predecessor: | Chuop Hell (acting) |
| Successor: | Chuop Hell (acting) |
| Office2: | Prime Minister of Cambodia |
| Monarch2: | Norodom Sihanouk |
| Term Start2: | 17 October 1945 |
| Term End2: | 15 December 1946 |
| Predecessor2: | Son Ngoc Thanh |
| Successor2: | Sisowath Youtevong |
| Birth Date: | 25 November 1909 |
| Birth Place: | Phnom Penh, Cambodia, French Indochina |
| Death Date: | September 1975 (aged) |
| Death Place: | Kampuchea |
| Blank1: | House |
| Data1: | Sisowath |
| Father: | Sisowath Monivong |
| Mother: | Norodom Kanviman Norleak Tevi |
| Spouse: | Pok Rosette Vani |
| Party: | Sangkum (1955–70) |
| Otherparty: | Independent (1945–55; 1970–75) |
| Allegiance: | |
| Serviceyears: | 1939–1945 |
| Branch: | French Foreign Legion[1] 5th Foreign Infantry Regiment |
| Battles: | World War II |
| Awards: | Legion of Honour Croix de guerre |
| Native Name Lang: | km |
Sisowath Monireth (Central Khmer: ស៊ីសុវត្ថិ មុន្នីរ៉េត; 25 November 1909 – September 1975)[2] was a Cambodian politician who served as the Prime Minister of Cambodia, during the French protectorate period, from 17 October 1945 to 15 December 1946. One of the most prominent members of the Sisowath line of the royal family at the time, he had earlier been passed over for the throne by the French authorities in favor of his nephew Norodom Sihanouk, whom they considered to be more pliable. The prince, however, remained heir to the throne under Sihanouk's reign.
From 1939 to 1945, he fought for France in World War II.[1]
The original Cambodian Scout movement Ankar Khamarak Kayarith was created in 1934, under the direction of Prince Sisowath Monireth and other leaders, including Tem Im and Pok Thiem. This first era of Cambodian Scouting spread over several provinces and numbered more than 1,000 members.
One of his first acts as Prime Minister was to create the first modern Cambodian army. Having won the consent of the French, who had just returned to power in Cambodia after the defeat of the Japanese in World War II, Monireth succeeded in forming out of former colonial NCOs the basis for an indigenous army whose mission, according to the Franco-Khmer Military Convention of 20 November 1946, was to uphold the sovereignty of the king, to preserve internal security, and to defend the frontiers of the country.[3]
In later years, Monireth temporarily acted as head of state from 6 April to 13 June 1960 in his capacity as Chairman of the Regency Council.
In 1975, he was executed by the Khmer Rouge after the Fall of Phnom Penh.