Summer, who won five Grammys and sold more than 130 million records worldwide, died surrounded by her family in Naples, Florida, publicist Brian Edwards said.
Edwards said she died of cancer but he declined to comment on a report from celebrity website TMZ.com that she had been diagnosed with lung cancer.
"Early this morning, surrounded by family, we lost Donna Summer Sudano, a woman of many gifts, the greatest being her faith. While we grieve her passing, we are at peace celebrating her extraordinary life and her continued legacy," the singer's family said in a statement.
Summer, known as the queen of disco, had three children and married twice. Her second husband, musician Bruce Sudano, was at her bedside, Edwards said.
She began her career in Germany where she performed in productions of the shows "Hair" and "Porgy and Bess" and worked as a studio session singer.
But it wasn't until 1975 that she found fame with the moaning vocals and grinding beat of "Love to Love You Baby" that was a huge, but controversial, hit in European nightclubs.
Summer followed up with a string of other disco tunes in the 1970s and into the mid-1980s, including "Last Dance," "Hot Stuff," "Bad Girls," "I Feel Love" and her cover version of the ballad "MacArthur Park," which was her first No. 1 record in the United States in 1978.
In 1983, she scored a massive hit with "She Works Hard for the Money," as she sought to branch out of the disco genre.
Summer's recording career declined in the 1990s, but she sang at Nobel Peace Prize concert in Norway in 2009 in honor of Nobel laureate, U.S. President Barack Obama.
Her family asked on Thursday that fans make donations in Summer's honor to the Salvation Army. (Reuters)
