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 Kevin Sussman Stuart Guest Star Brian Posehn Bert Guest Star Rati Gupta Anu Guest Star Pamela Adlon Halley Guest Star David Theune Dr. Graybel Guest Star Chuck Lorre Executive Producer Bill Prady Executive Producer Steven Molaro Executive Producer Steve Holland Writer Maria Ferrari Writer Tara Hernandez Writer Eric Kaplan Writer Jeremy Howe Writer Adam Faberman Writer Mark Cendrowski Director