Johnny Galecki Leonard Hofstadter Actor Jim Parsons Sheldon Cooper Actor Kaley Cuoco Penny Actor Simon Helberg Howard Wolowitz Actor Kunal Nayyar Raj Koothrappali Actor Mayim Bialik Amy Farrah Fowler Actor Melissa Rauch Bernadette Rostenkowski Actor Kevin Sussman Stuart Guest Star John Ross Bowie Barry Kripke Guest Star Megan Heyn Natalie Guest Star Patrika Darbo Grace Guest Star Rebecca Ann Johnson Attractive Red Head Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer Steven Molaro Executive Producer Eric Kaplan Writer Maria Ferrari Writer Steve Holland Writer Jim Reynolds Writer Saladin K. Patterson Writer Mark Cendrowski Director