Eötvös Loránd University (Hungarian: Eötvös Loránd Tudományegyetem, ELTE, also known as University of Budapest) is a public research university based in Budapest, Hungary. Founded in 1635, it is the longest continuously operating university in the country.

The almost 30 thousand students at ELTE are organized into nine faculties, and into research institutes located throughout Budapest and on the scenic banks of the Danube. ELTE is affiliated with 7 Nobel laureates, as well as winners of the Wolf Prize, Fulkerson Prize and Abel Prize, the latest of which was Nobel Prize in Literature winner László Krasznahorkai in 2025.

The predecessor of Eötvös Loránd University was founded in 1635 by Cardinal Péter Pázmány in Nagyszombat, Kingdom of Hungary (today Trnava, Slovakia) as a Catholic university for teaching theology and philosophy. In 1770, the university was transferred to Buda, later to Pest. It was named Royal University of Pest until 1873, then University of Budapest until 1921, when it was renamed Royal Hungarian Pázmány Péter University after its founder Péter Pázmány. The Faculty of Science started its autonomous life in 1949, when the Faculty of Theology and the Faculty of Medicine was separated from the university (now Pázmány Péter Catholic University and Semmelweis University). The university received its current name in 1950, after one of its most well-known physicists, Baron Loránd Eötvös.