The third season of the American television sitcom The Big Bang Theory aired on CBS from September 21, 2009 to May 24, 2010. It received higher ratings than the previous two seasons with over 15 million viewers. The third season saw the first appearances of future main cast members Melissa Rauch and Mayim Bialik as Bernadette Rostenkowski and Dr. Amy Farrah Fowler respectively. Christine Baranski was nominated for the Primetime Emmy Award for Outstanding Guest Actress in a Comedy Series at the 62nd Primetime Emmy Awards for the episode, "The Maternal Congruence". Jim Parsons won the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series for the episode "The Pants Alternative".

Cast

Main cast

Recurring cast

Guest cast

Special guest cast

Episodes

Ratings

Reception

The third season received critical acclaim. Maureen Ryan of Chicago Tribune who wrote that "Big Bang Theory, which is in its third season, is doing many things very right", Alan Sepinwall of The Star-Ledger wrote "the Penny/Sheldon interaction was gold, as always", and Ken Tucker of Entertainment Weekly, who wrote that "what lifts The Big Bang Theory into frequent excellence is its one constant from the start: the brilliantly nuanced performance of Jim Parsons". The American Film Institute ranked season three one of the ten best television seasons of 2009.