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 Marissa Cuevas Danielle Guest Star Brooke Baumer Denise Guest Star Nicole Butler Clerk Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer, Writer Steven Molaro Executive Producer Maria Ferrari Writer Adam Faberman Writer Steve Holland Writer Eric Kaplan Writer Tara Hernandez Writer Mark Cendrowski Director