Preap In (Khmer: ព្រាប អ៊ិន, 1938–1964) was a Cambodian political dissident of the 1950s–1960s. A high-level cadre of the Khmer Serei, a rightist militia formed to oppose the regime of Prince Norodom Sihanouk, In is remembered largely for an unsuccessful 1963 attempt to 'negotiate' directly with Sihanouk, resulting in his arrest and public execution by firing squad.