(This list is copied directly from the original page)

Conan O'Brien .... Host
Andy Richter .... Sidekick (1993-2000)
Max Weinberg .... Bandleader (Drums)
Joel Godard .... Announcer (voice)
rest of cast listed alphabetically
Christopher Bates .... Jeff Goldblum Stalker/Various (1994-1995)
Aaron Bergeron .... NBC Page with Jim Carrey/Various
Tommy Blacha .... Gaseous Wiener (1996-1998)
Andy Blitz .... Awful Ballgame Chanter/Chuck Aloo, star of 60/Leonard Diesel, Vin Diesel's Brother/Various
Jim Breuer .... Lips of Ozzy Osbourne (2002)
Dr. Joyce Brothers .... Frequent Cameos
Louis C.K. .... Nicknames for Conan Guy/Various (1993-1994)
Rob Corddry .... Various Characters (1998-2002)
Andrew Daly .... Various Characters (1998)
Tom Davis .... Dippy the Hippy (1995)
Michael Delaney .... Chat Room Audience Guy/Various
Jimmy DellaValle .... Various sketches
John Deyle .... Ray Burns: The People's Scientist (1996-1997)
Kevin Dorff .... Coked-Up Werewolf/Various Characters
Jennifer Estlin .... Conan's Girlfriend (as Jennifer Bill)
Ali Farahnakian .... Ari, Conan's Agent/Various Characters
Joe Fatale .... Little Jay Leno (2001-)
Jake Fogelnest .... Various (2001-)
Richard Francese .... Frank Tortelli the Pastel Teamster (2002)
Jon Glaser .... Jeremy/Segway Sam/Wrist Hulk/Pubes/Gordon Fisherman/Jingle Writer/Various (1996-2003)
Michael Gordon .... The Masturbating Bear/Dizz/Various
Julie Hays .... Various (1996-1999)
Scott Healy .... Max Weinberg 7 (Keyboards)
Hallee Hirsh .... Various Characters (1993-1997)
David Koechner .... NBC Gargoyle/Various (1996-1997)
Kyle Kulish .... Various (1995-1997)
Neil Maloney .... Johnny, the man who adores Catsup; various characters (1994)
Demitri Martin .... Nick Littleton: Tiny Stuntman/Various (2003-) (as Demetri Martin)
Jack McBrayer .... Various (2002-)
Brian McCann .... Preparation H Raymond/The Loser/Pimpbot 5000/Fed-Ex Pope/Bulletproof Legs Guy/Darren Rhodes/Airsick Moth/Various
Yvette Mercedes .... Homeless Christmas Caroler
Mike Merritt .... Max Weinberg 7 (Bass)
Shawn O'Toole .... Sketch Comedy (1993-2000)
Mark 'Love Man' Pender .... Max Weinberg 7 (Trumpet)
Eddie Pepitone .... Angry For Missing Tomorrow's Guests Guy/Various
Josh Perilo .... Various (2000- )
Jack Plotnick .... Slim Organbody (1995-1996)
Amy Poehler .... Stacy, Andy's little sister/Various (1996-2000)
William Preston .... Carl 'Oldy' Olsen (1993-1998)
Hardy Rawls .... Various Characters
Justin Restivo .... Bully
Jeff Richmond .... Russian Hat Guy/VD Cupid/Various
Debbie Rochon .... Various Sketches (1995)
Richie 'La Bamba' Rosenberg .... Max Weinberg 7 (Trombone)
Stelio Savante .... Antonio (1996)
Paul Scheer .... Ronald McDonald/Mike McKee/Robin Williams Swimsuit Model/Various
Andrew Secunda .... Jesus/Various
Chuck Sklar .... David Copperfield/Various Others
Robert Smigel .... Triumph the Insult Comic Dog/Lips of Bill Clinton/Lips of George W. Bush/Lips of Al Gore/Lips of Bob Dole/Lips of Arnold Schwarzenegger/Lips of Don King (voice)
Brian Stack .... Kilty McBagpipes/Ira/Frankenstein/Limbus the Late Night Psychic/Lips of Dick Cheney/Lips of Mike Tyson/Lips of Martha Stewart/Various
Dino Stamatopoulos .... Abraham Lincoln/Kiss-ass Turkey/Various (1993-1999)
Betsy Stover .... Various
Michael Straka .... Comedic Sketches
Dave Sweeney .... Missouri Senator
Mike Sweeney .... Abraham Lincoln (1999-)
Mio Takada .... Protected by 3 Inch Bees Guy
Richard Tokar .... Jimmy, the man who adores Ketchup; various other characters (1994)
Miriam Tolan .... Various
Abe Vigoda .... Frequent Cameos
Jerry Vivino .... Max Weinberg 7 (Saxophone)
Jimmy Vivino .... Max Weinberg 7 (Guitar)
Matt Walsh .... Neil Morris the Awful Prankster/Wussy Wagon Guy/Crazy Drunk Irish Guy/Dr. Frankenstein/Saint Patrick/Various
Linda Wang .... Conan's Asian Whore (1999)/The Masturbating Bear's Girlfriend (1997-1998)/Chinese Olympic
Jimmy Wormworth .... Max Weinberg 7 (Substitute Drummer)