Worked at a local grocery store during his teenage years.
Was voted Class Smart Alec at his home town high school, Broad Ripple High.
Started his TV career as a weekend weathercaster at an Indianapolis station.
He once congratulated a tropical storm for being upgraded to a hurricane.
Moved to LA in 1975 and worked as a stand up comedian and a writer for sitcoms such as Good Times and The Paul Lynde Comedy Hour.
Appeared briefly on shows such as The Starland Vocal Band, Mork & Mindy, and Mary Tyler Moore's variety series, Mary.
Big break came when Johnny Carson made him a regular guest host of the Tonight Show.
Was given his own daytime show in 1980. It lasted only three months before it was cancelled, but also earned two Emmy Awards.
Late Night with David Letterman debuted in 1982 and proved to be a huge success. On its 11.5 year run, it garnered five Emmy awards, and was honored with 35 nominations.
Signed a huge contract with CBS in 1992 to host The Late Show.
Received a George Foster Peabody award for taking "one of TV's most conventional and least inventive forms - the talk show - and infusing it with freshness and imagination."
Has been known to enjoy a good cigar, but recently "quit."
Is part owner of Team Rahal auto racing team (majority owner Bobby Rahal, 1986 Indianapolis 500 champion).
Funds a scholarship at Ball State University (his alma mater).
His production company, Worldwide Pants, produces "The Late Show," "The Late, Late Show" and "Everybody Loves Raymond."
His previous production companies include "Space Age Meat" and "Cardboard Shoe Productions."
Has appeared in movies such as "Cabin Boy," "Private Parts," and "Man on the Moon."
Before his quintuple heart bypass surgery (Jan. 2000), he had not missed a day due to illness in his 18 years of late-night.
Was chosen by TV Guide as one of the "50 Greatest TV Stars of All Time."