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 Regina King Janine Davis Guest Star Sophie Oda Grace Guest Star Aaron Takahashi Scientist Guest Star Alex Ball Waiter Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer Steven Molaro Executive Producer Steve Molaro Writer Tara Hernandez Writer Eric Kaplan Writer Jim Reynolds Writer Steve Holland Writer Mark Cendrowski Director