The Pro Football Hall of Fame announced Sayers' death. His son, Guy Bullard, told the New York Times that his father dad died as the result of complications of dementia and Alzheimer's disease. Sayers died at his home in Wakarusa, Ind.
"All those who love the game of football mourn the loss of one of the greatest to ever play this game with the passing of Chicago Bears legend Gale Sayers," Hall of Fame president David Baker said.
"He was the very essence of a team player -- quiet, unassuming and always ready to compliment a teammate for a key block. Gale was an extraordinary man who overcame a great deal of adversity during his NFL career and life."
Sayers was diagnosed with dementia in 2013. He used a wheelchair when he appeared at the Bears' 100 year anniversary celebration in 2019 at Soldier Field in Chicago.
"Sayers amplified what it meant to be a Chicago Bear both on and off the field," the Bears said. "He was regarded as an extraordinary teammate, leader, husband and father."
Sayers entered the NFL as the No. 4 overall pick in the 1965 NFL Draft and played his seven-year career with the Bears. The five-time All-Pro and four-time Pro Bowl selection dealt with numerous injuries, which shortened his professional football tenure.
"Will miss a great friend who helped me become the player I became because after practicing and scrimmaging against Gale I knew I could play against anybody," Hall of Fame linebacker Dick Butkus said in a statement.
"We lost one of the best Bears ever and more importantly we lost a great person."
Sayers was the 1965 Offensive Rookie of the Year and led the NFL in rushing yards in 1966 and 1969 before he was limited to just four games from 1970 through 1971 due to knee injuries. He was the league's all-time leader in kickoff return yards at the time of his retirement.
Sayers was inducted into the Pro Football Hall of Fame in 1977 and remains the youngest person in history (34) to receive the honor.
Sayers' friendship with Bears teammate Brian Piccolo -- who died of cancer in 1970 -- inspired Sayers' autobiography I am Third. The book inspired the 1971 movie Brian's Song. Actor Billy Dee Williams portrayed Sayers in the film.
"My heart is broken over the loss of my dear friend, Gale Sayers," Williams tweeted Wednesday. "Portraying Gale in Brian's Song was a true honor and one of the highlights of my career.
"He was an extraordinary human being with the the kindest heart."
Sayers, a Wichita, Kan., native was inducted into the College Football Hall of Fame in 1977. His jersey, No. 48, is retired at the University of Kansas and his jersey, No. 40, is retired by the Bears.
"The NFL family lost a true friend today with the passing of Gale Sayers," NFL Commissioner Roger Goodell said in a statement. "Gale was one of the finest men in NFL history and one of the game's most exciting players."
Sayers also served as the athletic director at Southern Illinois University from 1976 to 1981 after he retired from the NFL. He also founded a computer supply company.
He is survived by his wife, Ardythe Elaine Bullard, five sons and a daughter.
"The entire Pro Football Hall of Fame family mourns the passing of Gale," Baker said. "Our thoughts and prayers are with his wife, 'Ardie,' and their entire family. We will forever keep his legacy alive to serve as inspiration for future generations.
"The Hall of Fame flag will fly at half-staff until he is laid to rest."