Delbanco was born in White Plains, New York, the son of Jewish parents who fled from Germany to England before emigrating to the U.S. after the Second World War.

Delbanco taught at Harvard from 1981 to 1985 and since 1985 has been on the faculty of Columbia University, where, for twenty years, he held the Julian Clarence Levi Chair in the Humanities and, from 2005 to 2015, was the Mendelson Family Director of American Studies.

[3] In 2015, Delbanco gave a mini-lecture on Moby-Dick while riding with Stephen Colbert on the Nitro roller coaster at Six Flags Great Adventure amusement park in New Jersey.

In a controversial article published in 1999 in The New York Review of Books, he attributed to the contemporary English department “the contradictory attributes of a religion in its late phase—a certain desperation to attract converts, combined with an evident lack of convinced belief in its own scriptures and traditions.”[7] In subsequent articles, and in his book College: What It Was, Is, and Should Be (2012), based on the Stafford Little Lectures at Princeton, he traced the origins, development, and current state of higher education in the U.S.. Delbanco is an elected member of the American Philosophical Society and the American Academy of Arts and Sciences.

In 2012, he was awarded a National Humanities Medal by President Barack Obama for "his writings on higher education and the place classic authors hold in history and contemporary life."