Reddy's children Traci and Jordan confirmed the news of her death Tuesday in a public statement.
"She was a wonderful Mother, Grandmother and a truly formidable woman,” said the message. “Our hearts are broken. But we take comfort in the knowledge that her voice will live on forever."
The Australia-born musician was also known for her songs "Ain’t No Way To Treat a Lady," "Delta Dawn," "Angie Baby," "You and Me Against the World" and her cover of "I Don't Know How to Love Him," which is credited with putting her on the map.
Three of her songs reached No. 1, and she'd go on to win a Grammy Award for best female vocal pop performance for the feminist anthem "I Am Woman."
"I only have 10 seconds so I would like to thank everyone from Sony Capitol Records, I would like to think Jeff Wald because he makes my success possible and I would like to thank God because she makes everything possible," said Reddy during her acceptance speech.
The star previously said that she stopped singing once she realized the impact the song had made.
"That was one of the reasons that I stopped singing, was when I was shown a modern American history high-school textbook, and a whole chapter on feminism and my name and my lyrics (were) in the book," she told the AP. "And I thought, 'Well, I’m part of history now. And how do I top that? I can’t top that.' So, it was an easy withdrawal."
Reddy died just weeks after a biopic about her life was released.
Her music career began in Australia where she said she was considered "more of a jazz singer," but she altered her sound after winning a contest that brought her to the United States.
After her retirement, Reddy returned to Australia and earned a degree in clinical hypnotherapy.
The Associated Press contributed to this report