The university's athletic teams are members of the Missouri Valley Conference and the Missouri Valley Football Conference and are known as the “Redbirds," in reference to the state bird, the cardinal.

ISU was founded as a training school for teachers in 1857, the same year Illinois' first Board of Education was convened and two years after the Free School Act was passed by the state legislature. Among its supporters were judge and future Supreme Court Justice, David Davis and local businessman and land holder Jesse W. Fell whose friend, Abraham Lincoln, was the attorney hired by the board of education to draw up legal documents to secure the school's funding. Founded as Illinois State Normal University, its name was reflective of its primary mission as a normal school. Classes were initially held in downtown Bloomington, occupying space in Major's Hall, which was previously the site of Lincoln's “Lost Speech." With the completion of Old Main in 1860, the school moved to its current campus in what was then the village of North Bloomington, which was chartered as “Normal" in 1865. The new town had named itself after the university.

In 1965, the institution's name was changed to Illinois State University at Normal, and then again in 1968 to the current Illinois State University.

In accordance with its mission, the school's motto was originally “and gladly wold he lerne and gladly teche," in the Middle English spelling of Geoffrey Chaucer which has since been updated to modern English in the gender-neutral form “Gladly we Learn and Teach."