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 Kevin Sussman Stuart Guest Star Margo Harshman Alex Jensen Guest Star Josh Brener Dale Guest Star Kate Micucci Lucy Guest Star Briana Cuoco Gretchen Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Steve Holland Writer Steven Molaro Writer Jim Reynolds Writer Tara Hernandez Writer Mark Cendrowski Director