Feller died at 9:15 p.m. on Wednesday night of acute leukemia at a hospice, said Bob DiBiasio, the Indians vice president of public relations.
Remarkably fit until late in life, Feller had suffered serious health setbacks in recent months. He was diagnosed with a form of leukemia in August, and while undergoing chemotherapy, he fainted and his heart briefly stopped. Eventually, he underwent surgery to have a pacemaker implanted.
In November, he was hospitalized with pneumonia and Feller was recently released into hospice care.
Even as his health deteriorated, Feller continued doing what he loved most attending Indians games deep into last season.
"Nobody lives forever and I've had a blessed life," Feller said in September. "I'd like to stay on this side of the grass for as long as I can, though. I'd really like to see the Indians win a World Series."
Feller, in fact, was part of the rotation the last time the Indians won it all in 1948.
Fiercely proud and patriotic, Feller was an American original. He won 266 games during 18 seasons all with the Indians, who brought him up to the majors as a 17-year old. Feller's win total remains a Cleveland team record, one that seems almost untouchable in today's free-agent era.
Feller was part of a vaunted Indians' rotation in the 1940s and '50s with fellow Hall of Famers Bob Lemon and Early Wynn. He finished with 2,581 career strikeouts, led the American League in strikeouts seven times, pitched three no-hitters including the only one on opening day and recorded a jaw-dropping 12 one-hitters.
His numbers would no doubt have been even greater had his career not been interrupted by World War II.
The first pitcher to win 20 games before he was 21, Feller was enshrined in Cooperstown in 1962, his first year of eligibility.
The Indians retired his No. 19 jersey in 1957 and immortalized the greatest player in franchise history with a statue when they opened their downtown stadium in 1994. The sculpture is vintage Feller, captured forever in the middle of his patented windmill windup, rearing back to fire another pitch.