Burnett was born in San Antonio, Texas to two alcoholic parents, who left her with her grandmother, who moved to Hollywood, California. She graduated from Hollywood High School and the University of California, Los Angeles, and worked her way up through bit parts on TV to success in Broadway in the 1959 musical Once Upon a Mattress, and finally to headliner status in shows such as the 1962 special Julie and Carol and Carnegie Hall, also starring fellow singer/actress Julie Andrews.
The hour-long The Carol Burnett Show was a huge success, garnering 22 Emmy awardss and continuing to success in syndicated re-runs. Its ensemble cast included Tim Conway, Harvey Korman, and Vicki Lawrence, who was cast partly because she looked like a younger Burnett.
Burnett drew attention in 1981, when she sued the National Enquirer for libel after the tabloid newspaper described her alleged public drunkenness. The case is a landmark in the study of libel cases involving celebrities, although the unprecedented $1.6 million verdict was reduced on appeal, and the case was eventually settled out of court.
Burnett was a recipient of Kennedy Center Honors for 2003.