Friends and family are reportedly at her side, as support flooded in online from friends and fellow artists.
Known as the Queen of Soul, Aretha Franklin's career spans seven decades.
The 76-year-old cancelled planned concerts earlier this year due to health concerns and was ordered by doctors to rest for two months.
Last year she indicated her plans to retire from touring following the release of a new album.
Separately, celebrity website TMZ has also reported that a "long-time friend was told a week ago 'prepare yourself, she's dying.'"