Leonard Hofstadter

Johnny Galecki

Sheldon Cooper

Jim Parsons

Penny

Kaley Cuoco

Howard Wolowitz

Simon Helberg

Raj Koothrappali

Kunal Nayyar

Amy Farrah Fowler

Mayim Bialik

Bernadette Rostenkowski

Melissa Rauch

Mrs. Fowler

Kathy Bates

Stuart Bloom

Kevin Sussman

George

Jerry O'Connell

Janine Davis

Regina King

Beverly Hofstadter

Christine Baranski

Arthur Jeffries

Bob Newhart

Young Sheldon

Iain Armitage

President Siebert

Joshua Malina

Dr. Koothrappali

Brian George

Larry Fowler

Teller

Kripke

John Ross Bowie

Neil deGrasse Tyson

Neil deGrasse Tyson

Zack Johnson

Brian Thomas Smith

Wil Wheaton

Wil Wheaton

Wyatt Teller

Keith Carradine

Dr. Pemberton

Sean Astin

Debbie Wolowitz (voice)

Carol Ann Susi

Bert Kibbler

Brian Posehn

Dr. Campbell

Kal Penn

Tam

Robert Wu

George Sr.

Lance Barber

Dr. Park

Eddie Shin

Himself

Kevin Smith

Doctor Lee

Maribeth Monroe

Bill Nye

Bill Nye

Georgie

Montana Jordan

Himself

William Shatner

Nathan

Andy Daly

Andrea

Alison Martin

Bebe

Brooke Dillman

Maritza

Angela Lin

Halley Wolowitz (voice)

Pamela Adlon

Marissa

Lindsey Kraft

Anu

Rati Gupta

Denise

Lauren Lapkus

Karen

Chasty Ballesteros

Jess

Caleb Pierce

Greg

Shay Ali

Terry

Elijah Isaiah Cook

Neil

Eric Nenninger

Danny

Jason Kravits

Waiter

Matt Knudsen

Cynthia

Hira Ambrosino

Mitch

Todd Giebenhain

Himself

Joe Manganiello

Andy

Joel McCrary

Judge

Kurt Scholler

Bellman

Giovanni Bejarano

Trina

Mimi Gianopulos

Himself

Kip Thorne

Greg

Luis Aldana

Sunny Morrow

Ciara Renee

Dr. Graybel

David Theune

Colin

Hermie Castillo

Himself

George F. Smoot

Bob

Chip Chinery

Kwame

Andre Boyer

Himself

Kareem Abdul-Jabbar

Linda

Minerva García

Leslie

Kikey Castillo

Tour Guide

Andy Taylor Kim

Darren

Ben Rauch

Herself

Frances H. Arnold

Tour Guide

Andy Kim

Tour Group Member

Louis C. Robins

Stephen Hawking

Stephen Hawking

Althea

Vernee Watson-Johnson

Richard Williams

Dean Norris

Mike Rostenkowski

Casey Sander

Michael J. Massimino

Michael J. Massimino

Claire

Alessandra Torresani

Eric Gablehauser

Mark Harelik

Announcer (voice) / Man / Man V.O. (voice)

Ed Lieberman

Dimitri

Pasha D. Lychnikoff

Director

Joel Murray

Director

Mark Cendrowski

Director

Ted Wass

Director

James Burrows