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 Actor Mayim Bialik Amy Farrah Fowler Actor Brian George Dr. V.M. Koothrappali Guest Star Alice Amter Mrs. Koothrappali Guest Star Chriselle Almeida Lakshmi Choudry Guest Star Leonard Nimoy Mr. Spock Guest Voice Chuck Lorre Executive Producer Bill Prady Executive Producer Maria Ferrari Writer Steven Molaro Writer Jim Reynolds Writer Steve Holland Writer Mark Cendrowski Director