David Letterman
Self - Host (4252 eps)
Paul Shaffer
Self -Musical Director (4252 eps)
Alan Kalter
Self - Announcer (voice) (3813 eps)
Bill Wendell
Self - Announcer (voice) (439 eps)
Edd Hall
Voiceover Announcer (voice) (13 eps)
Scarlett Johansson
Self (4 eps)
Emily Blunt
Herself (1 eps)
Maggie Gyllenhaal
Herself (1 eps)
Neil Young
Himself (1 eps)
Harry Styles
Himself (1 eps)
Louis Tomlinson
Himself (1 eps)
Liam Payne
Himself (1 eps)
Zayn Malik
Himself (1 eps)
Niall Horan
Himself (1 eps)
Al Pacino
Himself (1 eps)
Miles Kath
Young Lettermen (1 eps)
Jessica Jung
Herself (1 eps)
Yoona
Herself (1 eps)
Taeyeon
Herself (1 eps)
Kwon Yu-ri
Herself (1 eps)
Hyoyeon
Herself (1 eps)
Sunny
Herself (1 eps)
Tiffany Young
Herself (1 eps)
Choi Soo-young
Herself (1 eps)
Seohyun
Herself (1 eps)
Susan Sarandon
Self (1 eps)
Whitney Cummings
Self (1 eps)
Angel Olsen
Self (1 eps)
Julio Iglesias
Self - Musical Guest (1 eps)
Gary Sinise
Self - Guest (1 eps)
Ricki Lake
Self - Guest (1 eps)
Cody Arens
Self (1 eps)
Alicia Keys
Self (1 eps)
Bruce Willis
Self (1 eps)
Julianna Margulies
Self - Guest (1 eps)
Eric Ripert
Self - Guest (1 eps)
Joe Seaward
Self - Musical Guest (1 eps)
Drew MacFarlane
Self - Musical Guest (1 eps)
Dave Bayley
Self - Musical Guest (1 eps)
Edmund Irwin-Singer
Self - Musical Guest (1 eps)
Lisa Howard
Lt. Genevieve Marshall (1 eps)
Tom Mison
Self - Guest (1 eps)
Taylor Swift
Self - Musical Guest (1 eps)
John Grant
Self (1 eps)
Nia Sanchez
Self (1 eps)
Christopher Walken
Self (1 eps)
Janelle Monáe
Self (1 eps)
Tatiana Maslany
Self (1 eps)
Regis Philbin
Self (1 eps)
Paul Morrissey
Self (1 eps)
Olivia Wilde
Self (1 eps)
Shep Gordon
Self (1 eps)
Dana Carvey
Self (1 eps)
Ellie Kemper
Self (1 eps)
Sam Smith
Self (1 eps)
Paul Rudd
Self (1 eps)
Jeff Altman
Self (1 eps)
Adam Levine
Self (1 eps)
Gen. Frank J. Grass
Self (1 eps)
Melissa McCarthy
Self (1 eps)
Rachelle Lefevre
Self (1 eps)
Lady Gaga
Self - Guest (1 eps)
Eric Stonestreet
Self - Guest (1 eps)
Justin Hayward-Young
Self - Musical Guest (1 eps)
Árni Árnason
Self - Musical Guest (1 eps)
Timothy Lanham
Self - Musical Guest (1 eps)
Yoann Intonti
Self - Musical Guest (1 eps)