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 John Ross Bowie Kripke Guest Star Jerry O'Connell Georgie Guest Star Christine Baranski Beverly Guest Star Beth Behrs Nell Guest Star Bob Newhart Arthur Jeffries Guest Star Brian Posehn Bert Guest Star Swati Kapila Ruchi Guest Star Wil Wheaton Himself Guest Star Laurie Metcalf Mary Guest Star Michelle Arthur Mrs. Petrescu Guest Star Pamela Adlon Halley Wolowitz Guest Voice Lauren Lapkus Denise Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Steven Molaro Executive Producer, Writer Eric Kaplan Writer Jeremy Howe Writer Adam Faberman Writer Steve Holland Writer David Goetsch Writer Maria Ferrari Writer Andrew Gordon Writer Tara Hernandez Writer Anthony Del Broccolo Writer Trevor Alper Writer Alex Yonks Writer Mark Cendrowski Director Nicole Lorre Director Anthony Rich Director