Johnny Galecki Leonard Hofstadter Actor Jim Parsons Sheldon Cooper Actor Kaley Cuoco Penny Actor Simon Helberg Howard Wolowitz Actor Kunal Nayyar Raj Koothrappali Actor Melissa Rauch Bernadette Rostenkowski Guest Star Mayim Bialik Amy Farrah Fowler Guest Star Wil Wheaton Wil Wheaton Guest Star Eric André Joey Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Jim Reynolds Writer Lee Aronsohn Writer Steven Molaro Writer Steve Holland Writer Mark Cendrowski Director