| Phra Phiset Phanit | |
| Office1: | Leader of Khmer Issarak |
| Term Start1: | 1940 |
| Term End1: | 1946 |
| Office2: | Member of Thai Parliament |
| Constituency2: | Phra Tabong |
| Term Start2: | 1946 |
| Term End2: | 1946 |
| Primeminister2: | Khuang Aphaiwong |
| Monarch2: | Ananda Mahidol |
| Office3: | Chairman of Khmer National Liberation Committee |
| Term Start3: | July 1949 |
| Term End3: | April 1950 |
| Predecessor3: | Dap Chhuon |
| Successor3: | Leav Keo Moni |
| Spouse: | Cha-on Aphaiwong |
| Profession: | Politician |
Phra Phiset Phanit (Thai: พระพิเศษพานิช), also known as Poc Khun (Central Khmer: ប៉ុក គុណ) or Wibun Pokmontri (Thai: วิบูล ปกมนตรี), was a member of the Aphaiwong branch of the Cambodian royal family, the brother-in-law of Prime Minister Khuang Aphaiwong of Thailand, and the organizer and leader of the first Khmer Issarak movement founded in 1940 to resist French colonial power in Cambodia.[1]
After the Khmer Issarak movement disintegrated due to internal political differences, Phiset was elected to represent Battambang (Phra Tabong) in the Thai parliament during the administration of his brother-in-law. After Khuang resigned as Prime Minister and Thailand again ceded the western Cambodian provinces back to French Indochina, Phiset and former Khmer Issarak members formed the Khmer National Liberation Committee (KNLC) in 1948 to further armed resistance against French rule of Cambodia. The KNLC attempted to distance itself from the Indochinese Communist Party and purge other leftists from within its own ranks paving the way for Phiset to become chairman in 1949. However, he was removed from that position less than a year later after being accused of misappropriating money designating for purchasing weapons.