Gregg was diagnosed with Parkinson's disease in 2011 after previous diagnoses of melanoma and colon cancer.
"The game lost a giant today. Forrest Gregg exemplified greatness during a legendary career that earned him a bronzed bust in Canton," Hall of Fame president and CEO David Baker said in a statement. "He was the type of player who led by example and, in doing so, raised the level of play of all those around him. Forrest symbolized many great traits and virtues that can be learned from this game to inspire people from all walks of life."
The former offensive lineman was a nine-time Pro Bowl selection and a six-time All-Pro. He played 15 seasons in the NFL with the Packers and Dallas Cowboys from 1956 to 1971. During his professional career, he played in a then-record 188 consecutive games. He was enshrined into the Pro Football Hall of Fame in 1977.
Gregg played at guard and tackle and won six NFL championships, including the first two Super Bowls with the Packers. He finished his playing career with a title victory with the Cowboys in 1971.