Leutner served as an instructor of Greek at Western Reserve's Flora Stone Mather College and Adelbert College in 1904. From 1905 to 1906, he was assistant professor of Greek at Wittenberg College, before returning to Adelbert College as an instructor of Latin and Greek in 1906. He again became instructor of Greek and Latin at Adelbert College from 1909 to 1915, becoming a full professor in 1915. In 1912 he became dean of Adelbert College, and in 1925 dean of university administration. Leutner helped establish Cleveland College, the downtown adult education college, where he was acting director from 1925 to 1926.[3]
In 1933 Leutner became the ninth president of Western Reserve University, serving until 1949.