Hymes left New York University, where he was studying chemistry, to pursue acting in the theater, but he changed course to join the U.S. Army during World War II, serving as a master sergeant in the Signal Corps.
He graduated from Adelphi University in 1949 and started at NBC in 1951.
Daughter is conductor Janna Hymes, and sons Tom Hymes is a former SNL writer and Jeff Hymes is a TV producer. Granddaughter Emily is a talent booker.