Yerevan State University (YSU; Armenian: Երևանի պետական համալսարան, ԵՊՀ, Yerevani petakan hamalsaran), also simply University of Yerevan, is the oldest continuously operating public university in Armenia. Founded in 1919, it is the largest university in the country. It is thus informally known as Armenia's "mother university" (Մայր բուհ, Mayr buh). Of its 3,150 employees, 1,190 comprise the teaching staff, which includes 25 academicians, 130 professors, 700 docents (associate professors), and 360 assistant lecturers. The university has 400 researchers, 1,350 post-graduate students, and 8,500 undergraduates, including 300 students from abroad.

Instruction is in Armenian, but instruction in Russian or English for foreign students is available as needed. The academic year is from September 1 through June 30.

According to University Ranking by Academic Performance (URAP), it was the top-ranked university in Armenia and the 954th in the world in 2010, of 20,000 institutions included in the list. Yerevan State University was listed among the 1,000 best universities of the world according to the QS World University Ranking 2022.

YSU is a full member of the International Association of Universities, European University Association (EUA), the Association of Eurasian Universities, the Russian Union of Rectors, the Association of Universities of the Countries of the Black Sea Region, and the International Association of Presidents of Universities.