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 Regina King Janine Davis Guest Star Ira Flatow Self 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 Anthony Del Broccolo Writer Mark Cendrowski Director