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 Brian Smith Zack Johnson Guest Star Carol Ann Susi Debbie Wolowitz Guest Voice Charlotte Newhouse Joy Guest Star Annie O'Donnell Mrs. Fowler Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Lee Aronsohn Writer David Goetsch Writer Steven Molaro Writer Steve Holland Writer Mark Cendrowski Director