Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.

Johnny Galeckias Leonard Hofstadter
Jim Parsonsas Sheldon Cooper
Kaley Cuocoas Penny
Simon Helbergas Howard Wolowitz
Kunal Nayyaras Rajesh Koothrappali
Melissa Rauchas Bernadette Rostenkowski
Mayim Bialikas Amy Farrah Fowler
Kevin Sussmanas Stuart Bloom
Laura Spenceras Emily Sweeney
Aarti Mannas Priya Koothrappali
Steven Molaro
Chuck Lorre
Bill Prady
Steve Holland
Maria Ferrari
Eric Kaplan
Jim Reynolds
Tara Hernandez
Jeremy Howe
David Goetsch
Lee Aronsohn
Saladin K. Patterson
Eddie Gorodetsky
Alex Yonks
David Saltzberg