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 Brian George Dr. Koothrappali Guest Star Brian Posehn Bert Guest Star Lauren Lapkus Denise Guest Star Luis Aldana Greg Guest Star Kikey Castillo Leslie Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer Steven Molaro Executive Producer, Writer Steve Holland Writer Maria Ferrari Writer David Goetsch Writer Eric Kaplan Writer Andrew Gordon Writer Mark Cendrowski Director