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 Actor Mayim Bialik Amy Farrah Fowler Actor William Stanford Davis Dry Cleaner Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer Eric Kaplan Writer Adam Faberman Writer Steven Molaro Writer Steve Holland Writer Mike Ferrari Writer Peter Chakos Director