The Phillies, the team Allen began his MLB career with, announced his death Monday on social media. No cause of death was given.
"The Phillies are heartbroken over the passing today of our dear friend and co-worker, Dick Allen," the Phillies said in a statement. "Dick will be remembered as not just one of the greatest and most popular players in our franchise's history, but also as a courageous warrior who had to overcome far too many obstacles to reach the level he did.
"Dick's iconic status will resonate for generations of baseball fans to come as one of the all-time greats to play America's Pastime. He is now reunited with his beloved daughter, Terri. The Phillies extend their condolences to Dick's widow, Willa, his family, friends and all his fans from coast to coast."
Allen, who was a seven-time All-Star, had a .292 batting average with 351 home runs and 1,119 RBIs in 15 seasons with the St. Louis Cardinals, Los Angeles Dodgers, Oakland Athletics, Phillies and White Sox.
Allen was named National League Rookie of the Year in 1964 while playing for the Phillies. He won the AL MVP award in 1972 after leading the league in home runs and RBIs as a member of the White Sox.
The Phillies retired Allen's No. 15 in September, a tribute that was considered long overdue by many for one of the organization's greatest players who battled racism during a turbulent period with the club in the 1960s.
Allen wasn't elected into the Baseball Hall of Fame, and he was one vote shy in Golden Era Committee voting in 2014. The Golden Days Committee and the Early Days Committee called off voting this year because of the coronavirus pandemic. The committees instead will meet sometime next winter.