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 Guest Star Aarti Mann Priya Koothrappali Guest Star Carol Ann Susi Debbie Wolowitz Guest Voice Eliza Dushku FBI Special Agent Angela Page Guest Star Mayim Bialik Amy Farrah Fowler Guest Star Neil deGrasse Tyson Neil deGrasse Tyson Guest Star Kevin Sussman Stuart Bloom Guest Star Brian George Dr. V.M. Koothrappali Guest Star Wil Wheaton Wil Wheaton Guest Star Joshua Malina President Siebert Guest Star Rick Fox Glenn Guest Star Brian Smith Zack Johnson Guest Star Alice Amter Mrs. Koothrappali Guest Star Eric André Joey Guest Star John Ross Bowie Barry Kripke Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Lee Aronsohn Writer David Goetsch Writer Eddie Gorodetsky Writer Adam Faberman Writer Steven Molaro Writer Eric Kaplan Writer Steve Holland Writer Jim Reynolds Writer Maria Ferrari Writer Mark Cendrowski Director Anthony Rich Director Howard Murray Director Peter Chakos Director