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 John Ross Bowie Kripke Guest Star Dean Norris Colonel Williams Guest Star Swati Kapila Ruchi Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer Steven Molaro Executive Producer Eric Kaplan Writer Tara Hernandez Writer Steve Holland Writer Maria Ferrari Writer Jeremy Howe Writer Anthony Rich Director