Ohio Northern University had a total enrollment of 3,140 students in 2024. The full-time enrollment at Ohio Northern University is 2,845 students and the part-time enrollment is 295. This means that 90.6% of students enrolled at Ohio Northern University are enrolled full-time.

The enrolled student population at Ohio Northern University, both undergraduate and graduate, is 77.2% White, 4.49% Two or More Races, 3.89% Hispanic or Latino, 3.03% Black or African American, 1.82% Asian, 0.127% Native Hawaiian or Other Pacific Islanders, and 0.0637% American Indian or Alaska Native.

Students enrolled at Ohio Northern University in full-time Undergraduate programs are most commonly White Male (43.8%), followed by White Female (36.2%) and Two or More Races Male (2.72%). Students enrolled in full-time Graduate programs are most commonly White Female (40%), followed by White Male (27.7%) and Black or African American Female (2.93%).