state university system of Missouri, U.S., comprising four coeducational campuses as well as an outreach and extension program. It is a land-grant university and one of the largest academic and research institutions in the United States—with some 550 degree programs, a total enrollment of some 60,000 students, and a large annual research budget. The main campus at Columbia provides comprehensive undergraduate, graduate, and professional degree programs and is divided into 17 schools and colleges. There are more than 90 graduate degree programs available. The Columbia campus has libraries containing more than 2.6 million volumes; among its research facilities is the University of Missouri-Columbia Research Reactor Center.

The branches of the University of Missouri at St. Louis and at Kansas City provide a wide array of degree programs; the college of arts and sciences is the largest division at each of these campuses. Particular to the Kansas City branch are the schools of dentistry and of pharmacy, the Conservatory of Music, and the School of Computing and Engineering. The St. Louis branch is known for its school of optometry and the Center for Metropolitan Studies. The campus at Rolla places heavy emphasis on science and technology; almost half the student body there is enrolled in the school of engineering. Notable areas of research at Rolla include the exploration, development, and utilization of energy resources; hazardous waste disposal; and global food supply. Both the Columbia and Kansas City campuses have law and medical schools.

Founded in Columbia in 1839, the University of Missouri became the first public university in the Louisiana Purchase territory and the oldest state university west of the Mississippi River. In 1870 it was approved as a land-grant university under the Morrill Act of 1862. The medical school was founded in 1841, the law school opened in 1872, and the world's first university course in journalism commenced in 1908. Progressive educator Junius L. Meriam (Meriam, Junius L.) established an experimental elementary school there in 1904.

The campus at Rolla was founded in 1870 as the Missouri School of Mines and Metallurgy, one of the first technological institutions in the United States; it was incorporated into the state university system in 1964. The campus at Kansas City was originally opened in 1933 as the privately owned University of Kansas City; it joined the system in 1963, the same year that the St. Louis campus was founded. Notable alumni of the University of Missouri include surgeon William Worrall Mayo and retail magnate Samuel Walton.