Oklahoma State University (informally Oklahoma State or OSU) is a public land-grant research university in Stillwater, Oklahoma, United States. The university was established in 1890 under the legislation of the Morrill Act. Originally known as Oklahoma Agricultural and Mechanical College (Oklahoma A&M), the Oklahoma State University campus in Stillwater is the flagship institution of the Oklahoma State University System, which enrolls more than 34,000 students across its five institutions with an annual budget of $1.89 billion for fiscal year 2026. As of Fall 2024, 27,241 students are enrolled at the university. OSU is classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, the university spent $226.5 million on research and development in 2023.