The third Hitopoulos brother inducted into the Carolinas Boxing Hall of Fame, Gregg was born on September 1, 1928. Although he did box for the University of South Carolina team, Hitopoulos made his mark as a trainer, coach, referee, and judge. While college boxing was coming to an end, he managed to fight 12 times without a defeat. During his year on the South Carolina team, he defeated three regional champions.
After graduation, he entered the U.S. Army, and upon his release Hitopoulos began to referee and judge matches, continuing for 12 years. He switched over to professional events where he refereed and judged fights for 20 years. He was helping his brother, Harry, coach the Citadel team at the same time.
Hitopoulos, a pharmacy major, operated two drug stores in Columbia before his death to cancer in 2004. He and his wife Charlotte were the parents of three children.