Caroll was born Carol Diahann Johnson in the Bronx, New York on July 17, 1935. She attended Music & Art High School and was classmates with Billy Dee Williams.
In 1975, she was nominated to the Best Leading Actress Academy Award for her role as Claudine in Claudine (1974, John Berry), co-starring James Earl Jones. She lost the statue to Ellen Burstyn for Alice Doesn't Live Here Anymore (1974, Martin Scorsese).
On October 4, 2019, Carroll died in Los Angeles, California of cancer at the age of 84.