public, coeducational institution of higher learning in Tahlequah, Oklahoma, U.S. It comprises six colleges covering arts and letters; business and industry; social and behavioral sciences; education; mathematics, science, and nursing; and optometry. In addition to undergraduate studies, the university's Graduate College offers more than a dozen master's degree programs and a doctorate in optometry. In 1993 it opened a branch campus in Muskogee; another branch campus opened in Broken Arrow in 2001. Courses and degrees may be taken on the campus of Oklahoma State University-Tulsa. Total enrollment exceeds 8,000.

The university's history began in 1846 with the establishment of National Male and Female seminaries by the Cherokee National Council, as specified by a provision of a treaty between the U.S. government and the Cherokee Nation (Cherokee). The two schools opened in 1851. In 1909 the state of Oklahoma bought the female seminary and established Northeastern State Normal School there to provide high school instruction and two years of college education. It became a four-year, degree-granting institution in 1919, when it was renamed Northeastern State Teachers College. It was elevated to university standing in 1974 and given its current name in 1985.

Northeastern State University has the largest enrollment of Native American students in the United States, making up about one quarter of total enrollment. The Center for Tribal Studies conducts research and supports Native American students and communities.