Season 5 of The Big Bang Theory returned to television in September 2011. The season ended in May 2012. In this season, Amy Farrah Fowler and Bernadette Rostenkowski become main characters with more screen time.
The season is mainly focused on Howard and Bernadette's wedding, the end of Leonard's long-distance relationship with Priya, Leonard and Penny experimenting in dating again, and Sheldon officially becomes Amy's boyfriend.
Cast
Main Cast
- Johnny Galecki as Leonard Hofstadter (24/24)
- Jim Parsons as Sheldon Cooper (24/24)
- Kaley Cuoco as Penny (24/24)
- Simon Helberg as Howard Wolowitz (24/24)
- Kunal Nayyar as Rajesh Koothrappali (24/24)
- Mayim Bialik as Amy Farrah Fowler (21/24)
- Melissa Rauch as Bernadette Rostenkowski (22/24)
Recurring Cast
- Aarti Mann as Priya Koothrappali (2/24)
- Brian George as V. M. Koothrappali (3/24)
- Alice Amter as Mrs. Koothrappali (3/24)
- Carol Ann Susi as Debbie Wolowitz (8/24)
- Wil Wheaton as Himself (2/24)
- Kevin Sussman as Stuart Bloom (6/24)
- John Ross Bowie as Barry Kripke (3/24)
- Mike Massimino as Himself (2/24)
- Joshua Malina as President Siebert (2/24)
- Casey Sander as Mike Rostenkowski (2/24)
- Ian Scott Rudolph as Captain Sweatpants (2/24)
Guest Cast
- Christine Baranski as Beverly Hofstadter
- Laurie Metcalf as Mary Cooper
- Vernee Watson as Althea Davis
- Pasha D. Lychnikoff as Dimitri Rezinov
- Stephen Hawking as Himself
- Katie Leclerc as Emily
- Courtney Ford as Alice
- Blake Berris as Kevin
- Ashley Austin Morris as Laura
- Josh Brener as Dale
- Lance Barber as Jimmy Speckerman
- Jonathan Schmock as Jonathan
- Jim Turner as Reverend White
- Becky O'Donohue as Siri
- Lynn Philip Seibel as Robb Rothman
- Peter Onorati as Angelo
- Chriselle Almeida as Lakshmi Choudry
- Robert Clotworthy as Dave Roeger
- Amy Tolsky as Joan
- Brent Spiner as Himself
- Leonard Nimoy as Spock
Episodes
| Episode (Series) | Episode (Season/Ep#) | Title | Original Air Date | Directed By | Description |
|---|---|---|---|---|---|
| 88 | 501 | The Skank Reflex Analysis | September 22, 2011 | Mark Cendrowski | Penny is worried with how damaged her friendship with the guys will be in the aftermath of her one-night stand with Raj while Sheldon becomes the leader of the paintball team. |
| 89 | 502 | The Infestation Hypothesis | September 22, 2011 | Mark Cendrowski | A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya. |
| 90 | 503 | The Pulled Groin Extrapolation | September 29, 2011 | Mark Cendrowski | Leonard accompanies Amy to a wedding. Meanwhile, Howard and Bernadette spend a weekend with Mrs. Wolowitz. |
| 91 | 504 | The Wiggly Finger Catalyst | October 6, 2011 | Mark Cendrowski | Penny finds the perfect girl for Raj to date. Meanwhile, Sheldon uses Dungeons & Dragons dice to make life's trivial decisions. |
| 92 | 505 | The Russian Rocket Reaction | October 13, 2011 | Mark Cendrowski | Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-world opportunity. |
| 93 | 506 | The Rhinitis Revelation | October 20, 2011 | Howard Murray | Sheldon competes with the gang for his mother's affection when she comes to visit. |
| 94 | 507 | The Good Guy Fluctuation | October 27, 2011 | Mark Cendrowski | A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween. |
| 95 | 508 | The Isolation Permutation | November 3, 2011 | Mark Cendrowski | Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her. |
| 96 | 509 | The Ornithophobia Diffusion | November 10, 2011 | Mark Cendrowski | Sheldon tries to cure his phobia of birds, while Leonard and Penny experiment with hanging out alone. |
| 97 | 510 | The Flaming Spittoon Acquisition | November 17, 2011 | Mark Cendrowski | When Stuart, from the comic book store, asks Amy out on a date, Sheldon becomes jealous and acts on their relationship. |
| 98 | 511 | The Speckerman Recurrence | December 8, 2011 | Anthony Rich | Leonard confronts his fears when he is contacted by a bully who tormented him in high school. |
| 99 | 512 | The Shiny Trinket Maneuver | January 12, 2012 | Mark Cendrowski | Howard and Bernadette deal with the possibility of ever having a child, while Sheldon and Amy encounter the first bump in their relationship. |
| 100 | 513 | The Recombination Hypothesis | January 19, 2012 | Mark Cendrowski | Leonard decides to invite Penny out on a dinner date, hoping to rekindle their relationship. |
| 101 | 514 | The Beta Test Initiation | January 26, 2012 | Mark Cendrowski | Leonard and Penny deal with the possibility of a reconciliation and Raj finally finds a "woman" that he can talk to without being drunk; the Siri in his new iPhone. Meanwhile, Amy helps Sheldon start a new YouTube series called "Sheldon Cooper presents Fun with Flags". |
| 102 | 515 | The Friendship Contraction | February 2, 2012 | Mark Cendrowski | Tired of being more like Sheldon's chauffeur than his roommate, Leonard invokes Clause 209 of The Roommate Agreement that allows him to be only an acquaintance. Meanwhile, Howard has been chosen by NASA to go into space and tries to get a neat nickname. |
| 103 | 516 | The Vacation Solution | February 9, 2012 | Mark Cendrowski | Forced to undergo his mandatory vacation by President Siebert, Sheldon decides to join Amy at her laboratory, only to find himself struggling to do things right. Meanwhile, Bernadette and Howard face the issue of signing a prenuptial agreement, at her father's insistence. |
| 104 | 517 | The Rothman Disintegration | February 16, 2012 | Mark Cendrowski | Sheldon and Kripke engage in sporting activities to battle each other out in order to find the winner of who will get the newly vacated Robb Rothman's office. Meanwhile, Penny feels uncomfortable with Amy's friendship gift. |
| 105 | 518 | The Werewolf Transformation | February 23, 2012 | Mark Cendrowski | Sheldon's world turns upside-down when his barber gets sick. Meanwhile, astronaut training gets Howard to rethink his decision to join the upcoming mission to space. |
| 106 | 519 | The Weekend Vortex | March 8, 2012 | Mark Cendrowski | Leonard plans a marathon video game event for the gang the same weekend Amy wants Sheldon to go to her aunt's birthday party. |
| 107 | 520 | The Transporter Malfunction | March 29, 2012 | Mark Cendrowski | Sheldon opens his mint-condition vintage Star Trek transporter -- a gift from Penny which he ends up breaking. Meanwhile, Raj asks his parents to set him up with someone. |
| 108 | 521 | The Hawking Excitation | April 5, 2012 | Mark Cendrowski | When Howard gets the opportunity to work with Stephen Hawking, Sheldon will do whatever it takes to meet him. |
| 109 | 522 | The Stag Convergence | April 26, 2012 | Peter Chakos | The guys organize a bachelor's party for Howard, which leads to the unraveling of Howard's secrets. Bernadette accidentally hears about them, threatening their impending nuptials. |
| 110 | 523 | The Launch Acceleration | May 3, 2012 | Mark Cendrowski | Howard's launch date gets pushed up, coinciding on the same week as his wedding, putting him in a dilemma. Leonard endangers his relationship with Penny with a sudden proposal to her, and Sheldon finds himself developing feelings for Amy after a few gestures from her. |
| 111 | 524 | The Countdown Reflection | May 10, 2012 | Mark Cendrowski | Howard and Bernadette decide to elope after their wedding is put off to enable Howard to join NASA's mission to the International Space Station. |