The fourth season of the American sitcom The Big Bang Theory aired on CBS from September 23, 2010 to May 19, 2011. Melissa Rauch and Mayim Bialik auditioned and were promoted to the main cast during this season as Dr. Bernadette Rostenkowski and Dr. Amy Farrah Fowler respectively.

Eliza Patricia Dushku is an American actress. She is best known for starring as Faith in the supernatural drama series Buffy the Vampire Slayer (1998–2003) and its spin-off series Angel (2000–2003). She also had lead roles in the Fox supernatural drama series Tru Calling (2003–2005) and the Fox science fiction series Dollhouse (2009–2010), for which she was a producer.