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 Posehn Bert Kibbler Guest Star Michelle Arthur Mrs. Petrescu Guest Star Josh Banday Nolan Guest Star Bryan Safi Daniel Guest Star Tucker Albrizzi Christopher Guest Star Jareb Dauplaise Jeff Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer Steven Molaro Executive Producer Steve Holland Writer Tara Hernandez Writer Jeremy Howe Writer Steve Molaro Writer Saladin K. Patterson Writer Anthony Del Broccolo Writer Mark Cendrowski Director