Johnny Galecki Leonard Hofstadter Actor Jim Parsons Sheldon Cooper Actor Kaley Cuoco Penny Actor Simon Helberg Howard Wolowitz Actor Kunal Nayyar Raj Koothrappali Actor Melissa Rauch Bernadette Rostenkowski Guest Star Mayim Bialik Amy Farrah Fowler Guest Star Brian George Dr. V.M. Koothrappali Guest Star Alice Amter Mrs. Koothrappali Guest Star Aarti Mann Priya Koothrappali Guest Star Brian Greene Brian Greene Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Eric Kaplan Writer Eddie Gorodetsky Writer Steven Molaro Writer Steve Holland Writer Mark Cendrowski Director