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 Vernee Watson Althea Guest Star Pamela Adlon Halley Wolowitz Guest Voice Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer Steven Molaro Executive Producer Steve Holland Writer Maria Ferrari Writer Steve Molaro Writer Eric Kaplan Writer Tara Hernandez Writer Nicole Lorre Director