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 Bob Newhart Arthur Jeffries Guest Star Joshua Malina President Siebert Guest Star Eddie Shin Dr. Park Guest Star Alison Martin Andrea Guest Star Hermie Castillo Colin Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer Steven Molaro Executive Producer Eric Kaplan Writer Andrew Gordon Writer Alex Ayers Writer Steve Holland Writer Maria Ferrari Writer Tara Hernandez Writer Mark Cendrowski Director