Naomi Judd died near Nashville, Tennessee, said a statement on behalf of her husband and fellow singer, Larry Strickland.
It said no further details about her death would be released and asked for privacy as the family grieves.
The mother-daughter performers scored 14 No. 1 songs in a career that spanned nearly three decades.
After rising to the top of country music, they called it quits in 1991 after doctors diagnosed Naomi Judd with hepatitis C. Wynonna continued her solo career.