Frances Wolff, known professionally as Fran Warren, was an American singer. She was born into a Jewish family in the New York City borough of the Bronx.

After some time in a chorus line at the Roxy Theater, she joined Art Mooney's big band and worked with Billy Eckstine, who gave her the name "Fran Warren". She spent almost two years with the Charlie Barnet band before achieving some recognition with Claude Thornhill. In 1947, she reached the music charts for the first time with the song "A Sunday Kind of Love" written by her manager, Barbara Belle.