The Royal University of Phnom Penh (RUPP; Khmer: សាកលវិទ្យាល័យភូមិន្ទភ្នំពេញ, Sakalvityealai Phumin Phnom Penh [saːkɑlʋɨtjiəlaj pʰuːmɨn pʰnom pəɲ]; French: Université royale de Phnom Penh) is a national research university of Cambodia, located in the Phnom Penh capital. Established in 1960, it is the country's largest university. It hosts around 30,000 students in undergraduate and postgraduate programmes. It offers degrees in fields such as sciences, humanities and social sciences, environment, engineering as well as vocational courses in fields such as information technology, electronics, psychology and tourism. RUPP provides Cambodia's foremost degree-level language programmes through the Institute of Foreign Languages. RUPP has full membership in the ASEAN University Network (AUN).

RUPP has over 420 full-time staff. All of its 294 academic staff hold tertiary qualifications, including 24 PhDs and 132 Master's degrees. They are supported by 140 administrative and maintenance staff. The university maintains linkage networks with Cambodian and international NGOs, universities and government ministries. As a result, international and non-government organizations and government offices regularly contribute adjunct faculty members to help expand RUPP's capacity.

The Royal University of Phnom Penh began as the Royal Khmer University (Khmer: សាកលវិទ្យាល័យខេមរភូមិន្ទ, Sākalvidyālăy Khemarabhūmind; French: Université royale khmère) in 1960. It opened during a period of intense growth in Cambodia and expanded to include a National Institute of Judicial and Economic Studies, a Royal School of Medicine, a National School of Commerce, a National Pedagogical Institute, a Faculty of Letters and Human Sciences, and a Faculty of Science and Technology. The language of instruction during this period was French.

With the growth of Cambodia's economy and an assertion of its historical role, modern buildings for that time were constructed in the style of the New Khmer Architecture, which has influences of Bauhaus, European post-modern architecture, and traditions from Angkor.

With the establishment of the Khmer Republic in 1970, the university became the Phnom Penh University (Khmer: សាកលវិទ្យាល័យភ្នំពេញ; French: Université de Phnom Penh). Between 1965 and 1975 there were nine faculties: the Ecole Normale Supérieure (Higher Normal College), Letters and Humanities, Science, Pharmacy, Law and Economics, Medicine and Dentistry, Commerce, Pedagogy, and the Languages Institute.

The Democratic Kampuchea period of 1975–1979 saw the closure and destruction of schools, the decimation of the teaching service and the cessation of formal education at the hands of the Khmer Rouge. Phung Ton, the rector of Phnom Penh University, was arrested, tortured and murdered at Tuol Sleng (S-21). During this period, Phnom Penh University and all other educational institutions in Cambodia were closed down. Under this regime an education was perceived as a dangerous asset. Hence, the educated were targeted, and most of the university's teachers and students were killed. The campus was abandoned and remained deserted for almost five years. Of the educated people who survived, few remained in Cambodia once the borders reopened following the Vietnamese invasion that toppled Khmer Rouge rule.

In 1980, under the People's Republic of Kampuchea, the Ecole Normale Supérieure (Higher Normal College) reopened, again teaching predominantly in French. In 1981, the Institute of Foreign Languages (IFL) began, initially training students to become Vietnamese and Russian teachers. The purpose of both colleges was to provide surviving graduates of primary school or above with crash courses in teaching.

In 1988, the college and the IFL merged to create Phnom Penh University, and in 1996 the name was changed to the Royal University of Phnom Penh.