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 Wil Wheaton Wil Wheaton Guest Star John Ross Bowie Barry Kripke Guest Star Ira Flatow Ira Flatow Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer Steven Molaro Executive Producer, Writer Eric Kaplan Writer Jim Reynolds Writer Maria Ferrari Writer Steve Holland Writer Adam Faberman Writer Mark Cendrowski Director