Comedy doyenne and TV sketch queen Carol Burnett is set to receive the Mark Twain Prize for American Humor.

The Kennedy Center for the Performing Arts in Washington, which administers the prize, announced the former TV stalwart as this year's pick, on Tuesday.

"From her television program and appearances, as well as her performances on Broadway and in film, Carol Burnett has entertained generations of fans with her vibrant wit and hilarious characters," Kennedy Center chair David Rubenstein said in a statement, which dubbed the performer a "unique and beloved entertainer."

In turn, the 80-year-old quipped: "I can't believe I'm getting a humour prize from the Kennedy Center. It's almost impossible to be funnier than the people in Washington."

She will be celebrated on Oct. 20 at a star-studded Washington gala that will be recorded and broadcast later that month on PBS. 

Hollywood-raised Burnett, who appeared on stage and film as well as television, is best known for her long-running variety program The Carol Burnett Show. On air from 1967 to 1978 and drawing an average of 30 million viewers a week, the Emmy-winning program included appearances by fellow performers such as Lucille Ball, Jimmy Stewart, Ronald Reagan and Betty White. In 2007, it was dubbed one of the 100 best television shows of all time by Time magazine.

Established in 1998, the Twain Prize honours comedians, satirists and those who have had an impact on society in the tradition of Samuel Clemens, better known as Mark Twain. Burnett will join past honorees such as Richard Pryor, Steve Martin, Tina FeyGeorge Carlin and Ellen DeGeneres, who won in 2012.