San Diego State University (SDSU) is a public research university in San Diego, California, United States. Founded in 1897, it is the third-oldest university and southernmost in the 23-member California State University (CSU) system. SDSU is the oldest higher education institution in San Diego; its academic roots were established as a normal school in University Heights, then known as the San Diego Normal School. In the fall of 2024, the university enrolled over 38,000 students.