The Complutense University of Madrid (UCM) is the oldest public university in Madrid and is considered one of the most important and prestigious universities in Spain and the Spanish-speaking world. According to most international rankings, the Complutense University ranks among the top 100 universities in the world and is one of the 70 best in Europe. It is also recognised for its degrees in Dentistry, Veterinary Medicine and Modern Languages, which are ranked in the top 50 internationally, while its degrees in Pharmacy, Geography, History, Archaeology, Anthropology, Linguistics, Classical Philology, Communication and Law are among the top 100 in the world. In addition, it is currently the 3rd largest on-campus university on the European continent, the greenest university in Spain and one of the 50 greenest on the planet. 

It has three campuses: the Ciudad Universitaria campus, the Somosaguas campus and the Chamberí-Centro campus, in addition to the historic building located in the centre of Madrid, on Calle de San Bernardo. It was founded in 1822 by bringing together in a single institution the teachings taught in different centres.

Internationally, the Complutense University has cooperation agreements with some of the most prestigious universities in the world, such as Oxford University, the University of Paris 1 Pantheon-Sorbonne, the University of Rome "La Sapienza", Harvard University, the University of Chicago and the University of California at Berkeley. With Harvard University he signed the agreement that allowed the creation of the Royal Complutense College at Harvard, which aims to promote intellectual and scientific academic exchange.

The Complutense University of Madrid is made up of 26 faculties, 9 affiliated centres, 39 university institutes, 7 professional specialisation schools, 184 departments, 36 departmental sections, 13 university clinics and hospitals, 18 Research Support Centres (CAI) and Singular Scientific-Technological Installations (ICTS), 38 halls of residence and 32 libraries.