O'Day died in her sleep early Thursday morning at a convalescent hospital in Los Angeles where she was recovering from a bout with pneumonia, said her manager Robbie Cavolina.
"On Tuesday night, she said to me, get me out of here," Cavolina said. "But it didn't happen."
Once known as the "Jezebel of Jazz" for her reckless, drug-induced lifestyle, O'Day lived to sing and she did so from her teen years until this year when she released "Indestructible!"
"All I ever wanted to do is perform," she said in a June 1999 interview with The Associated Press. "When I'm singing, I'm happy. I'm doing what I can do and this is my contribution to life."
Cavolina recently completed a feature film about O'Day and accompanied her to shows and on tours.
"She got to see how many people really loved her at the shows we did, in New York, in London," Cavolina said. "She had come back after all of this time. She really lived a very full and exciting life."
O'Day was born in Chicago, Ill. She left home at age 12 and often bragged about being "self-made" and never having a singing lesson.
She began her career in her teens and later recorded hits with Stan Kenton and Gene Krupa. Her highly stylized performance of songs like "And Her Tears Flowed Like Wine," "Let Me Off Uptown," "Honeysuckle Rose" and "Sweet Georgia Brown" made her famous the world over.
In her prime, O'Day was described as a scat singer and a natural improviser whose unique interpretations energized the most familiar songs. She inspired many singers, including June Christy and Chris Connor.
Her fame came at a price.
She suffered from a 16-year heroin addiction and an even longer alcohol problem. Wild, drug-related behavior and occasional stints in jail on drug charges earned her the nickname "Jezebel of Jazz," a term she hated.
"I tried everything," she once said. "Curiosity will make you go your own way."
She overdosed many times and on one occasion in the late 1940s, it was almost fatal.
The experience shocked her into giving up drugs, but she continued to drink.
Her 1981 memoir "High Times Hard Times" tells of her long struggle with drug addiction and her romance with drummer John Poole.
In late 1996, O'Day fell down the stairs of her Hemet, Calif., home after a drinking binge. She was admitted to a hospital with a broken arm but ended up with severe food poisoning and pneumonia.
She survived the ordeal but her recovery — both physical and emotional — was painful. She left the hospital in a wheelchair and didn't walk for nearly a year. Her right hand was paralyzed but worst of all, she said, she had lost her singing voice.
Although she blamed the complications on poor hospital care, the near-death experience convinced O'Day to give up alcohol.
It took nearly a year to get her voice back and start singing again. But once she did, she was right back on stage.
She received a lifetime achievement award from the National Endowment for the Arts in 1997.
For the last years of her life, O'Day performed at various Los Angeles night spots.
O'Day had no children and no immediate family, Cavolina said.