The University of California, Berkeley is a major research university located in Berkeley, California, United States. Informally referred to by such abbreviations as Cal, California, UC Berkeley, and simply Berkeley, it is the oldest of the ten campuses affiliated with the University of California. Berkeley offers some 300 undergraduate and graduate degree programs in a wide range of disciplines. The university occupies with the central campus resting on approximately .

The University was founded in 1868 in a merger of the private College of California and the public Agricultural, Mining, and Mechanical Arts College. By the 1930s, Berkeley had established itself as a premier research university, and today counts sixty-one Nobel Laureates among its faculty, researchers and alumni. Berkeley physicists led and hand-picked the team of scientists who worked on the Manhattan Project, which developed the atomic bomb during World War II and the hydrogen bomb soon afterwards. The University has managed Lawrence Berkeley National Laboratory and the nation's two principal nuclear weapons labs (now also used for more peaceful research) at Livermore, California, and Los Alamos, New Mexico, ever since.

Among their many achievements, Berkeley scientists invented the cyclotron, discovered the antiproton, played a key role in developing the laser, explained the processes underlying photosynthesis, isolated the polio virus, designed experiments that confirmed Bell's theorem, created the widely used BSD Unix computer operating system, and discovered numerous transuranic elements on the Periodic Table, including seaborgium, plutonium, berkelium, lawrencium and californium. Berkeley's faculty also continue to sustain a distinguished record in fields outside the physical sciences: they have received three Fields Medals in mathematics as well as four Nobel Prizes in economics, one Nobel Prize in literature, three Pulitzer Prizes, 28 MacArthur Fellowships, 92 Sloan Fellowships, 384 Guggenheim Fellowships, seven Wolf Prizes, and nine James S. McDonnell Foundation awards.

Berkeley student-athletes compete intercollegiately as the California Golden Bears. A member of both the Pacific-10 Conference and the Mountain Pacific Sports Federation in the NCAA, Cal students have won national titles in many sports, including football, men's basketball, baseball, softball, water polo, rugby and crew. In addition, they have won over 100 Olympic medals. The official colors of the university and its athletic teams are Yale blue and California gold.