As a graduate student, Lentz served as a teaching fellow at
Vanderbilt University between 1964 and 1969. In 1969, he returned to
Kenyon College, where he has spent his entire career, being appointed assistant professor of English in 1969, associate professor in 1973, and then full professor. He was subsequently appointed to an academic chair, McIlvaine Professor of English, and has served as chairman of the English Department. He was a
Woodrow Wilson Fellow in 1964 and held a
Rockefeller Foundation grant in 1971. In 1978–79, he was visiting professor at
Exeter University in England, where he established a joint program with Kenyon. Lentz was twice awarded
Trustee Teaching Excellence Award, in 1992 and 2009
. In honor of his distinguished tenure and teaching excellence,
Kenyon College opened the Lentz House for its Department of English in 2009. Lending his name to the new English building places Lentz in the ranks of other highly distinguished Kenyon faculty, such as
John Crowe Ransom, for whom Ransom Hall, Kenyon's Admissions building, was renamed in 1958. In a video uploaded to the
Vlogbrothers YouTube channel, author
John Green, whom Lentz taught at Kenyon, listed Lentz's "Instruction Booklet" as one of his most valuable books. ==Published works==