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 Aarti Mann Priya Koothrappali Guest Star Kevin Sussman Stuart Bloom Guest Star Courtney Ford Alice Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer David Goetsch Writer Maria Ferrari Writer Steven Molaro Writer Steve Holland Writer Mark Cendrowski Director