The University of the Philippines Diliman (Filipino: Unibersidad ng Pilipinas Diliman), also referred to as UPD, UP Diliman, or simply University of the Philippines or UP, is a coeducational, public research university located in Diliman, Quezon City, Philippines. It was established on February 12, 1949, as the flagship campus and seat of administration of the University of the Philippines System, the national university of the Philippines.
It is the fourth oldest and is the largest constituent campus of the University of the Philippines System in terms of the number of degree-granting academic units, student population, faculty, and library resources. There are 27 degree-granting units on campus, accounting for 22,031 students of which, 15,299 are undergraduates. UP Diliman had a complement of 1,526 full-time faculty in 2012, of whom 528 have doctoral degrees.In addition to the units in the main campus, UP Diliman has extension programs in Angeles City, Pampanga (the Clark Freeport Zone area) and Olongapo, Zambales, as well as a marine laboratory in Bolinao, Pangasinan under the Marine Science Institute, and an annex campus at Bonifacio Global City, Taguig. UP Diliman offers academic programs in 247 major fields. There are 70 programs at the undergraduate level, 109 at the master's level and 68 at the doctoral level.The UP Diliman campus is also the site of the country's National Science Complex. Notable research units of UP Diliman centered at the National Science Complex include the Marine Science Institute (MSI), the National Institute of Geological Sciences (NIGS), the National Institute of Physics (NIP), the National Institute of Molecular Biology and Biotechnology–Diliman (NIMBB-Diliman), and the National Institute for Science and Mathematics Education Development (NISMED), which are all pioneers of scientific research and development in the Philippines. The Sentro ng Wikang Filipino, devoted to research on the intellectualization of the Filipino language is also located in the campus.