Stephen Colbert will replace David Letterman on the Late Show.
The 49-year-old host, who currently fronts The Colbert Report, will be taking over from the 66-year-old star on the CBS show when he retires next year.
Stephen said in a statement: "Simply being a guest on David Letterman's show has been a highlight of my career. I never dreamed that I would follow in his footsteps, though everyone in late night follows Dave's lead. I'm thrilled and grateful that CBS chose me. Now, if you'll excuse me, I have to go grind a gap in my front teeth."
Stephen hosts his Comedy Central show, which he has fronted since 2005, in the character of a conservative cable news anchor and, although the late-night program will finish its run in eight months time, it is not yet known whether his alter-ego will live on.
A spokesman for CBS said: "Stephen Colbert is one of the most inventive and respected forces on television."
Meanwhile, David announced last week he was stepping down from his hosting duties on the flagship show, which he has fronted for 20 years.
David is the longest-serving late night talk show host in TV history after fronting NBC's Late Night for 11 years, before taking on the Late Show in 1993.