Glenn Evans Derby, Jr. (born June 27, 1964) is a former American football offensive lineman in the National Football League. He played three seasons for the New Orleans Saints (1988–1990) as a tackle, guard and center. He went to Green Bay Packers as a free agent and left after injury in 1991. He played at the collegiate level at the University of Wisconsin–Madison.
Derby is the brother of former NFL player John Derby. His nephew, A. J. Derby, a tight end, played for the New England Patriots and is now with the Denver Broncos.