David Michael Letterman is an American television host, comedian, writer and producer. He hosted late-night television talk shows for 33 years, beginning with the February 1, 1982, debut of Late Night with David Letterman on NBC and ending with the May 20, 2015, broadcast of Late Show with David Letterman on CBS. In total, Letterman hosted 6,080 episodes of Late Night and Late Show, surpassing his friend and mentor Johnny Carson as the longest-serving late-night talk show host in American television history.

Letterman was born in Indianapolis, Indiana, in 1947, and has two sisters, one older and one younger. His father, Harry Joseph Letterman (April 15, 1915 – February 13, 1973), was a florist. His mother, Dorothy Marie Letterman Mengering (née Hofert; July 18, 1921 – April 11, 2017), a church secretary for the Second Presbyterian Church of Indianapolis, was an occasional figure on Letterman's show, usually at holidays and birthdays.

Letterman has tinnitus, a symptom of hearing loss. On the Late Show in 1996, he talked about his experience with tinnitus during an interview with William Shatner, who has severe tinnitus caused by an on-set explosion. Letterman has said that he was initially unable to pinpoint the noise inside his head and that he hears a constant ringing in his ears.