The University of Barcelona (Universitat de Barcelona, UB) is a public research university in Barcelona, the capital of Catalonia, Spain. Its charter dates to 3 November 1450, when Alfonso V of Aragon granted the city the right to run a general studium at the request of the Consell de Cent, formalising the medical and arts school that Martin of Aragon had tried to establish in 1401. The institution was suppressed in the early eighteenth century under the Nueva Planta decrees, which concentrated Catalan higher education in Cervera. Teaching returned to Barcelona in 1837, the modern university was constituted in 1842, and its neo-Romanesque main building, designed by Elies Rogent, took its first classes in 1871.

Its faculties are spread over several campuses in and around the city. The historic building on Plaça de la Universitat houses philology and communication alongside mathematics and computer science, while philosophy, geography and history moved in 2006 to purpose-built premises in the Raval district. The Diagonal campus, the largest, concentrates law, economics and business, fine arts, biology, pharmacy and food sciences, physics, earth sciences and chemistry. Education and psychology are based at Mundet, information and audiovisual media at Sants, and food science teaching also takes place at Torribera. Enrolment is roughly 62,000 students across bachelor's, master's and doctoral levels, with instruction in Catalan and Spanish.

Research is carried out by more than 240 research groups recognised by the Government of Catalonia and by some thirty research centres and institutes. Medicine and the health sciences are tied to two teaching hospitals: the Campus Clínic at the Hospital Clínic de Barcelona, and the Bellvitge health sciences campus in L'Hospitalet de Llobregat. Associated research foundations include IDIBAPS, IDIBELL, the Institute for Research in Biomedicine and the Barcelona Science Park. The university library holds around two million volumes, the second largest such collection in Spain, and the UB belongs to networks including LERU and the Coimbra Group.