Louis Glanzman began his career in the late 1930s drawing for comic books published by Centaur Comics. He illustrated 'Air Man', 'Amazing Man', 'The Shark', 'Dopey Danny Day' and 'Blue Fire'. He was also present in True Comics and Real Heroes by Parents' Magazine Press. In the 1940s he also served as an illustrator on the Air Force magazine for the US Air Forces.
He was furthermore an illustrator for Life, Collier's, Seventeen and Time Magazine, where he stood out for his portraits. From the 1950s through the 1970s, he illustrated for several juvenile books, such as the 'Pippi Longstocking' and 'Tom Corbett' series. He also made illustrations for paperbacks, as well as magazines like Boy's Life, National Geographic and National Lampoon. He is the brother of comic book artists Sam Glanzman and Davis Glanzman.