According to O'Brien, NBC executive Warren Littlefield told him that the show would never succeed unless O'Brien fired Andy Richter, whom Littlefield referred to as a "fat dildo."

According to O'Brien, the show was cancelled during the first season, but NBC realized that they had nothing to replace it. NBC renewed the show a few weeks at a time.

After head writer Robert Smigel left to work on The Dana Carvey Show (1996), O'Brien offered staff writer Louis C.K. the position. C.K. turned it down and followed Smigel to Carvey's show.

Al Roker has the record for the most appearances on the show, with over thirty. Al Franken is second with over twenty-five. The reason for their numerous appearances is that both Als are usually the "go to" guys whenever another guest cancels because they live so close to the studio. This has been brought up and joked about on more than one Al Franken appearance.

Dana Carvey was NBC's original choice for the new host of Late Night once David Letterman announced he was leaving to go to CBS. Carvey turned down the offer, but hosted a primetime variety show, The Dana Carvey Show (1996), for ABC. This short-lived series has been considered a good indicator of what his version of Late Night might have been like, since it shared regular Late Night with Conan O'Brien writers such as Robert Smigel and Louis C.K. on its staff.

Jon Stewart, Drew Carey, Paul Provenza, and Allan Havey are among the comedians who auditioned for the job of hosting the show.

O'Brien auditioned on the set of The Tonight Show with Jay Leno (1992). His guests were Jason Alexander and Mimi Rogers.

In the first show, O'Brien jogged out from behind the curtains to his mark for the opening monologue. As time went on, he would try new things (in one show, he just jumped up and down to his mark). Eventually, he adopted this "shuffle", where he would walk hunched over and have his arms shuffling at his sides. When the show returned to air for the first time after the terrorist attacks on the U.S. of September 11 2001, he replaced the shuffle with a more subdued walk, which he continued to use as his entrance until the final episode.

Frequent sketches include: The Walker Texas Ranger Lever, In The Year 2000, Celebrity Survey, Stamps, Actual Items, What In The World?, If They Mated, New State Quarters, Clutch (talking lips), Conan on the Aisle, SAT analogies, et cetera.

On May 15, 2003, there was a special claymation episode, where the entire show was done with animated clay figures. The guests for that show included Johnny Knoxville, Richard Lewis, and David Bowie.

Tony Bennett appeared once a year as the musical guest, and always during Christmastime.

According to former NBC Vice President Warren Littlefield, Howard Stern was aggressively pursued to replace O'Brien during the low-rated early years.

The guests on the premiere episode were John Goodman, Drew Barrymore, and Tony Randall.

Radiohead was the first musical guest on the show. The last was The White Stripes.

Generally, shows were taped at 5:30 p.m. Tuesday through Friday.

The staff would refer to the opening monologue as the "Conologue".

From April 22 - 25, 2003, The White Stripes was the musical guest for an entire week. According to NBC, that marks the longest stint for any guest band in late night television history.

Green Brook, New Jersey had shoots with Nipsy Russell and Max Weinberg. The Nipsy bit was of him stealing a boat with a rifle, about which production failed to notify the town. The police arrived, but locals recognized him. The town then helped keep people from yelling "Hey, there's Nipsy Russell!" during takes.

Garry Shandling was NBC's first choice to replace David Letterman. He declined, because he was launching The Larry Sanders Show (1992). Letterman suggested Dana Carvey as a replacement.