The University of California, Irvine (UCI, UC Irvine, or Irvine) is a public research university located in Irvine, California, USA and one of the ten campuses of the University of California (UC). UCI is the fifth-largest campus in the UC system with nearly 28,000 students, 1,100 faculty members and 9,000 staff.

UCI was one of three new UC campuses established in the 1960s to accommodate growing enrollments across the UC system. In 1960, The Irvine Company sold the University of California 1,000 acres (400 ha) of land for one dollar to establish a new campus and U.S. President Lyndon B. Johnson dedicated the campus in 1964. The city of Irvine, designed by the university architect and The Irvine Company around the university as a master-planned community, was incorporated in 1971. UCI is a large research university with eight undergraduate schools and two graduate schools offering 84 undergraduate degrees and 98 graduate and professional degrees. The university has a very high level of research activity ($324.5 million in research and development expenditures in 2009) and was inducted into the Association of American Universities in 1996. UCI also administers the UCI Medical Center and UC Irvine Health Sciences system in the city of Orange, the University of California, Irvine, Arboretum, and a portion of the University of California Natural Reserve System.

The UC Irvine Anteaters compete in 18 men's and women's sports in the NCAA Division I as members of the Big West Conference and the Mountain Pacific Sports Federation. Since 1969, the university has won 26 national team championships in nine different sports and has had 63 individual national champions. 90% of UCI students are from California and Asian Americans make up 53% of the undergraduate student population.