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 Joshua Malina President Siebert Guest Star John Ross Bowie Kripke Guest Star Maribeth Monroe Doctor Lee Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer Steven Molaro Executive Producer Eric Kaplan Writer Anthony Del Broccolo Writer Alex Yonks Writer Steve Holland Writer David Goetsch Writer Maria Ferrari Writer Mark Cendrowski Director