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 Kevin Sussman Stuart Bloom Guest Star John Ross Bowie Barry Kripke Guest Star Brian Smith Zack Johnson Guest Star Aarti Mann Priya Koothrappali Guest Star LeVar Burton LeVar Burton Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer David Goetsch Writer Maria Ferrari Writer Steven Molaro Writer Jim Reynolds Writer Mark Cendrowski Director