Johnny Galecki
Leonard Hofstadter (279 eps)
Jim Parsons
Sheldon Cooper (279 eps)
Kaley Cuoco
Penny (279 eps)
Simon Helberg
Howard Wolowitz (279 eps)
Kunal Nayyar
Rajesh Koothrappali (279 eps)
Melissa Rauch
Bernadette Rostenkowski (221 eps)
Mayim Bialik
Amy Farrah Fowler (217 eps)
Kevin Sussman
Stuart Bloom (84 eps)
Carol Ann Susi
Debbie Wolowitz (voice) (40 eps)
Wil Wheaton
Wil Wheaton (17 eps)
Christine Baranski
Beverly Hofstadter (16 eps)
Brian Posehn
Bert Kibbler (15 eps)
Joshua Malina
President Siebert (13 eps)
Brian Thomas Smith
Zack Johnson (11 eps)
Pamela Adlon
Halley Wolowitz (voice) (10 eps)
Rati Gupta
Anu (9 eps)
Lauren Lapkus
Denise (8 eps)
Stephen Hawking
Stephen Hawking (7 eps)
Vernee Watson-Johnson
Althea (6 eps)
Dean Norris
Richard Williams (6 eps)
Casey Sander
Mike Rostenkowski (6 eps)
Michael J. Massimino
Michael J. Massimino (6 eps)
Regina King
Janine Davis (6 eps)
Bob Newhart
Arthur Jeffries (6 eps)
Alessandra Torresani
Claire (5 eps)
Mark Harelik
Eric Gablehauser (5 eps)
Ed Lieberman
Announcer (voice) (5 eps)
Keith Carradine
Wyatt Teller (5 eps)
Pasha D. Lychnikoff
Dimitri (5 eps)
Margo Harshman
Alex Jensen (4 eps)
Robert Clotworthy
Train Conductor (voice) (4 eps)
Brian Patrick Wade
Kurt (3 eps)
LeVar Burton
LeVar Burton (3 eps)
Riki Lindhome
Ramona Nowitzki (3 eps)
Kimberly Brooks
Computer (voice) (3 eps)
Swati Kapila
Ruchi (3 eps)
Stephen Merchant
Dave Gibbs (3 eps)
Marcus Folmar
Security Guard (3 eps)
Ira Flatow
Ira Flatow (3 eps)
Sara Rue
Stephanie Barnett (3 eps)
Kevin Brief
Glen (3 eps)
Ian Scott Rudolph
Captain Sweatpants (uncredited) (3 eps)
Jerry O'Connell
Georgie Cooper (3 eps)
Kathy Bates
Mrs. Fowler (3 eps)
Teller
Larry Fowler (3 eps)
Kal Penn
Kevin Campbell (3 eps)
Sean Astin
Greg Pemberton (3 eps)
Travis Schuldt
Eric (2 eps)
Michael Trucco
David Underhill (2 eps)
Jodi Lyn O'Keefe
Mikayla (2 eps)
Lewis Black
Professor Crawley (2 eps)
Yeardley Smith
Sandy (2 eps)
Eliza Dushku
Angela Page (2 eps)
Rick Fox
Glenn (2 eps)
Jessica Walter
Mrs. Latham (2 eps)
Michael Hyatt
Charlotte (2 eps)
Will Deutsch
Jeremy (2 eps)
Valerie Azlynn
Alicia (2 eps)
Erin Allin O'Reilly
Cheryl (2 eps)
James Hong
Chen (2 eps)
Blake Berris
Kevin (2 eps)
Courtney Ford
Alice (2 eps)
Stephen Root
Dan (2 eps)
Dakin Matthews
Santa Claus (2 eps)
Jim Meskimen
Minister (2 eps)
Elena Campbell-Martinez
Maria (2 eps)
Alex Ball
Waiter (2 eps)
Judd Hirsch
Alfred Hofstadter (2 eps)
Annie O'Donnell
Mrs. Lorvis (voice) (2 eps)
Molly Morgan
Hostess (2 eps)
Katie Leclerc
Emily (2 eps)
Katee Sackhoff
Self (2 eps)
David Trice
Waiter (2 eps)
Josh Brener
Dale (2 eps)
Lance Barber
Jimmy Speckerman (2 eps)
Lio Tipton
Vanessa Bennett (2 eps)
Bill Nye
Bill Nye (2 eps)
Neil deGrasse Tyson
Neil deGrasse Tyson (2 eps)
Courtney Henggeler
Missy Cooper (2 eps)
Chasty Ballesteros
Karen (2 eps)
David Theune
Dr. Graybel (2 eps)
Michelle Arthur
Mrs. Petrescu (2 eps)
Kevin Smith
Kevin Smith (2 eps)
Caleb Pierce
Jess (2 eps)
Lindsey Kraft
Marissa Johnson (2 eps)
Ellen DeGeneres
Ellen DeGeneres (2 eps)
George F. Smoot
George F. Smoot (2 eps)
Octavia Spencer
Octavia (1 eps)
Summer Glau
Self (1 eps)
Elizabeth Bogush
Catherine Millstone (1 eps)
Julio Oscar Mechoso
Officer Hackett (1 eps)
Judy Greer
Elizabeth Plimpton (1 eps)
Steve Wozniak
Self (1 eps)
George Takei
Self (1 eps)
Kimberly Kevon Williams
Vicki (1 eps)
Andrew W. Walker
Mike (1 eps)
Emma Degerstedt
Emma (1 eps)
Peter Onorati
Angelo (1 eps)
Brooke D'Orsay
Christy Vanderbel (1 eps)
Oliver Muirhead
Professor Laughlin (1 eps)
Danica McKellar
Abby (1 eps)
Sherry Weston
Dance Instructor (1 eps)
Joel Brooks
Professor Goldfarb (1 eps)
Allen Nabors
Doug (1 eps)
Rachel Cannon
Patty (1 eps)
Billy Bob Thornton
Oliver Lorvis (1 eps)
Kara Luiz
Jeanie (1 eps)
James Earl Jones
Self (1 eps)
Carrie Fisher
Self (1 eps)
DJ Qualls
Toby Loobenfeld (1 eps)
Sarayu Blue
Lalita Gupta (1 eps)
Michael Reetz
Photographer (1 eps)
Noel De Souza
Older Indian Man (1 eps)
Nathan Fillion
Nathan Fillion (1 eps)
Angela Relucio
Hostess (1 eps)
Stephanie Escajeda
Cindy (1 eps)
Max Adler
Zombie (1 eps)
Tate Ellington
Mitchell (1 eps)
Michael Dempsey
Security Guard (1 eps)
Mark Barrett
Security Guard #2 (voice) (1 eps)
Matt Bennett
Josh Wolowitz (1 eps)
Rena Strober
Caller (voice) (1 eps)
Sara Erikson
Gwen (1 eps)
Kelli Goss
Chelsea (1 eps)
Phoebe Neidhardt
Casting Assistant (1 eps)
Jeff Jingle
Alien (voice) (1 eps)
Mark Maitre
Alien #2 (voice) (1 eps)
Max Mittelman
Tech Support (voice) (1 eps)
Katherine Von Till
Tech Support Recording (voice) (1 eps)
Louise Claps
Receptionist (1 eps)
Melissa Tang
Mandy Chao (1 eps)
Craig Welzbacher
Candidate #1 (1 eps)
Kurt Koehler
Candidate #2 (1 eps)
Arshad Aslam
Candidate #3 (1 eps)
Megan Heyn
Natalie (1 eps)
Patrika Darbo
Grace (1 eps)
Rebecca Ann Johnson
Attractive Red Head (1 eps)
Michael Rapaport
Kenny Fitzgerald (1 eps)
Troy Winbush
Paramedic (1 eps)
Sophie Oda
Grace (1 eps)
Aaron Takahashi
Scientist (1 eps)
Barak Hardley
Pizza Delivery Guy (1 eps)
Christine Corpuz
Woman (1 eps)
Todd Eric Andrews
Dr. Gunderson (1 eps)
Ayumi Iizuka
Scientist (1 eps)
Adam Nimoy
Self (1 eps)
Elon Musk
Elon Musk (1 eps)
Wayne Wilderson
Travis (1 eps)
Yoshi Barrigas
Trent Monaco (1 eps)
Becky O'Donohue
Siri (voice) (1 eps)
Jane Kaczmarek
Dr. Gallow (1 eps)
June Squibb
Connie Tucker (1 eps)
Adam West
Self (1 eps)
Creagen Dow
Glenn the Maitre D' (1 eps)
Shane Blades
Customer (1 eps)
Bruce Holman
Airport Pedestrian (1 eps)
Jim Holmes
Tim (1 eps)
Michael Croner
Andre (1 eps)
Blake Anderson
Trevor (1 eps)
Katey Sagal
Susan Teller (1 eps)
Jack McBrayer
Randall Teller (1 eps)
Josh Zuckerman
Marty (1 eps)
Brandon W. Jones
The Flash (1 eps)
Bryan Safi
Daniel (1 eps)
Tucker Albrizzi
Christopher (1 eps)
Jareb Dauplaise
Jeff (1 eps)
Maria Canals-Barrera
Issabella (1 eps)
Christopher Lloyd
Theodore (1 eps)
Joel Murray
Doug (1 eps)
April Bowlby
Rebecca (1 eps)
Phil Abrams
Dr. Bernstein (1 eps)
Susan Chuang
Dr. Harris (1 eps)
George Wyner
Dr. Zane (1 eps)
Monica Garcia Pérez
Maria (1 eps)
Kaliko Kauahi
Marta (1 eps)
Casper Smart
Travis (1 eps)
Steve Valentine
Kenneth (1 eps)
Kimberly Hebert Gregory
Ms. Davora (1 eps)
Phyllis Timbes
Voicemail (voice) (1 eps)
Fernando Rivera
Salesperson (1 eps)
Rod Keller
Wardrobe Person (1 eps)
Gilda Stratton
Flight Attendant (voice) (1 eps)
Christopher Neiman
Dr. Dreyfus (1 eps)
Eric Petersen
Eric (1 eps)
Tania Raymonde
Yvette (1 eps)
Josh Peck
Jesse (1 eps)
Morgan Hewitt
Lizzy (1 eps)
Tom Fonss
Student (1 eps)
Beth Behrs
Nell (1 eps)
Talbott Lin
Chinese Leonard (1 eps)
Walton Goggins
Oliver (1 eps)
Charlie Sheen
Self (1 eps)
Zachary Abel
Todd (1 eps)
Stan Lee
Self (1 eps)
Frank Maharajh
Venkatesh Koothrappali (1 eps)
Howard Chan
Chinese Sheldon (1 eps)
Judith Moreland
Jan (1 eps)
Sarah Buehler
Sarah (1 eps)
Ally Maki
Joyce Kim (1 eps)
Artie O'Daly
Young Man (1 eps)
Ryan Cartwright
Cole (1 eps)
Sierra Edwards
Summer (1 eps)
Treisa Gary
Waitress (1 eps)
Jennifer Hale
News Announcer (voice) (1 eps)
Emily Happe
Kathy O'Brien (1 eps)
Ronald Hunter
Dan (1 eps)
Tyler Jon Olson
Blaine (1 eps)
Livia Treviño
Lourdes (1 eps)
Travis Davis
Ground Controller (voice) (1 eps)
Jane Galloway Heitz
Mildred (1 eps)
Andy Mackenzie
Skeeter (1 eps)
Steve Paymer
Judge J. Kirby (1 eps)
Steven Yeun
Sebastian (1 eps)
William Stanford Davis
Dry Cleaner (1 eps)
Jim Turner
Reverend White (1 eps)
Chuck Carter
Stan (1 eps)
Sandra Marquez
Woman (1 eps)
Eric André
Joey (1 eps)
Lauri Johnson
Mrs. Gunderson (1 eps)
Ajgie Kirkland
Louie (1 eps)
Arnold Chun
Ho-Jun (1 eps)
Tiffany Dupont
Angela (1 eps)
Ashley Austin Morris
Laura (1 eps)
Stacey Travis
Sandy (1 eps)
Buzz Aldrin
Self (1 eps)
Chriselle Almeida
Lakshmi Choudry (1 eps)
Nick Clifford
Phil (1 eps)
Meagen Fay
Mrs. Rostenkowski (1 eps)
Jonathan Schmock
Jonathan (1 eps)
Karl T. Wright
Jimmy (1 eps)
Matt Battaglia
Officer Reynolds (1 eps)
Tiffany Daniels
Clerk (1 eps)
Dana L. Wilson
Dr. Sanders (1 eps)
Sergio Enrique
Son (1 eps)
Charlotte Newhouse
Joy (1 eps)
Whitney Avalon
Elsie (1 eps)
Lanny Joon
Officer Shin (1 eps)
Sharon Omi
Nurse in Biohazard Suit (1 eps)
Tom Yi
Dispatcher (voice) (1 eps)
Janelle Marra
Claire (1 eps)
Jadon Sand
Aaron (1 eps)
Lynn Philip Seibel
Professor Rothman (1 eps)
Piper Mackenzie Harris
Girl #1 (1 eps)
Riccardo LeBron
Tom (1 eps)
Angela Sargeant
Lana (1 eps)
Marissa Cuevas
Danielle (1 eps)
Michael Patrick McGill
Police Officer (1 eps)
Eric Normington
Man (1 eps)
Brian Greene
Self (1 eps)
Chris Reed
Todd Zarnecki (1 eps)
Dusan Brown
Jeremy (1 eps)
Ken Lerner
Dr. Schneider (1 eps)
Craig Gellis
Car Thief #1 (1 eps)
Diamond White
Girl #2 (1 eps)
Paul Willson
Professor Sharpe (1 eps)
Jeff Witzke
Moviegoer (voice) (1 eps)
Josh Banday
Nolan (1 eps)
Amanda Payton
Ainsley (1 eps)
Brooke Baumer
Denise (1 eps)
Elka Rodriguez
Rose Lady (1 eps)
Jan Hoag
Lillian (1 eps)
Amy Tolsky
Joan (1 eps)
Frank Alvarez
Car Thief #2 (1 eps)
Briana Cuoco
Gretchen (1 eps)
Dawson Fletcher
Justin (1 eps)
Nicole J. Butler
Clerk (1 eps)
Endre Hules
Russian Mission Control (voice) (1 eps)
John Mendoza
Chauffeur (1 eps)
Rick Gifford
Guy (1 eps)
Bill Gates
Bill Gates (1 eps)
Giovanni Bejarano
Bellman (1 eps)
Ciara Renée
Sunny Morrow (1 eps)
Andy Taylor Kim
Tour Guide (1 eps)
Luis Aldana
Greg (1 eps)
Kikey Castillo
Leslie (1 eps)
Matt Knudsen
Waiter (1 eps)
Robert Wu
Tam Nguyen (1 eps)
Eddie Shin
Dr. Park (1 eps)
Alison Martin
Andrea (1 eps)
Hermie Castillo
Colin (1 eps)
Iain Armitage
Sheldon Cooper (1 eps)
Montana Jordan
Georgie Cooper (1 eps)
Kurt Scholler
Judge (1 eps)
Mark Hamill
Mark Hamill (1 eps)
Maribeth Monroe
Dr. Lee (1 eps)
Hira Ambrosino
Cynthia (1 eps)
Hugh Kennedy
Chad (1 eps)
Keili Lefkovitz
Brenda (1 eps)
Andy Daly
Nathan (1 eps)
Joel McCrary
Andy (voice) (1 eps)
Eric Nenninger
Neil (1 eps)
Joe Manganiello
Joe Manganiello (1 eps)
Kareem Abdul-Jabbar
Kareem Abdul-Jabbar (1 eps)
William Shatner
William Shatner (1 eps)
Jason Kravits
Danny (1 eps)
Ben Rauch
Darren (1 eps)
Brooke Dillman
Bebe (1 eps)
Doreen Calderon
Woman #1 (1 eps)
Sarah Eagen
Woman #2 (1 eps)
Claudia Choi
Woman #3 (1 eps)
Tiffany Commons
Woman #4 (1 eps)
Krishna Smitha
Woman #5 (1 eps)
Angela Lin
Maritza (1 eps)
Elijah Isaiah Cook
Terry (1 eps)
Todd Giebenhain
Mitch (1 eps)
Blair Hickey
Reporter #2 (1 eps)
Dinora Walcott
Reporter #1 (1 eps)
Rodney J. Hobbs
Reporter #3 (1 eps)
Sarah Michelle Gellar
Sarah Michelle Gellar (1 eps)
Adam Gregor
Dmitri (1 eps)
Jen Drohan
Martha (1 eps)
Parvesh Cheena
Marcus (1 eps)
Bob Stephenson
Wendell (1 eps)
Megan McGown
Cynthia (1 eps)
Neil Gaiman
Neil Gaiman (1 eps)
Patrick Daniel
Grant (1 eps)
Peter MacNicol
Robert Wolcott (1 eps)
James Maslow
Bartender (1 eps)
Edward James Gage
Nicholas (1 eps)
Mark Berry
Pit Boss (1 eps)
Evan Charest
Croupier (1 eps)
D'Kia Anderson
Hostess (1 eps)
Seth Coltan
Earl (1 eps)
Ellie Reed
Jenna (1 eps)
Mark Hames
Tom (1 eps)
Samantha Potter
Model (1 eps)
Jade Zdanow
Rebecca (1 eps)
Jason Mesches
Denny (1 eps)
Leonard Nimoy
Mr. Spock (voice) (1 eps)
Cynthia Holloway
Roberta (1 eps)
Declan Churchill Carter
Five Year Old (1 eps)
Doug Morency
Stranger (1 eps)
Cat Hammons
Nurse (1 eps)
Joey Rich
Man (1 eps)
Jeffrey Cade Ross Brown
Toby (1 eps)
Rachna Khatau
Kathleen (1 eps)
Laura Cerón
Marta (1 eps)
Eileen Galindo
Letty (1 eps)
Lynn Andrews
Margaret (1 eps)
Shay Ali
Greg (1 eps)
Chip Chinery
Bob (1 eps)
Minerva García
Linda (voice) (1 eps)
Hilda Boulware
Woman (1 eps)
Andre Boyer
Kwame (1 eps)
Frances H. Arnold
Frances H. Arnold (1 eps)
Kip Thorne
Kip Thorne (1 eps)
Susan Leslie
Woman #6 (1 eps)
Cassidey Fralin
Woman #7 (1 eps)
Riley Go
Woman #8 (1 eps)
Cleo Fraser
Little Girl (1 eps)
Thomas Albany
Carl XVI Gustaf of Sweden (1 eps)
Sailah Nicol
Halley Wolowitz (1 eps)
Nate Ash
Michael Wolowitz (1 eps)
Ulf Bjorlin
Announcer (1 eps)
Major Mike
Daniel Westling (1 eps)
Stephane Nicoli
Guy at the Movies (uncredited) (1 eps)
Howie Mandel
Howie Mandel (1 eps)
Jesse Heiman
Comic Book Store Customer (uncredited) (1 eps)
Seaonna Chanadet
Eye Rolling Girl Student (uncredited) (1 eps)
Bryan Stamp
Library Graduate Student (uncredited) (1 eps)
David Barrera
Officer Hernandez (1 eps)
Anil Margsahayam
Man (1 eps)
Tonja Kahlens
Woman (1 eps)
Robert Noble
Older Gentleman (1 eps)
Malcolm Foster Smith
Roy (1 eps)
Michael Araujo
Stadium Announcer (voice) (1 eps)
Netta Most
American Shopper (uncredited) (1 eps)
Efrain Gomez
Employee (1 eps)
Jeanelle Marie Cruz
Bike Messenger (uncredited) (1 eps)
Austin Lee
Dennis Kim (1 eps)
Meli Alexander
Cheesecake Factory Patron (1 eps)