On Tuesday, March 21, 2017, it was announced that The Big Bang Theory would be renewed for two more seasons after Season 10, which means there is a Season 11 and a Season 12. It was thought that Season 12 would be the last TBBT season, due to comments by the cast members. CBS confirmed that Season 12 is the last season.
- Johnny Galecki as Leonard Hofstadter (8/24)
- Jim Parsons as Sheldon Cooper (8/24)
- Kaley Cuoco as Penny Hofstadter (8/24)
- Simon Helberg as Howard Wolowitz (8/24)
- Kunal Nayyar as Rajesh Koothrappali (8/24)
- Mayim Bialik as Amy Farrah Fowler (8/24)
- Melissa Rauch as Bernadette Rostenkowski-Wolowitz (8/24)
- Kevin Sussman as Stuart Bloom (recurring/main cast) (4/24)
|Title||Original Air Date||Directed By||Description|
|256||1201||The Conjugal Configuration||September 24, 2018||Mark Cendrowski||The Coopers are on their honeymoon in New York City, the Hofstadters find Larry Fowler hiding in Shamy's apartment and Raj has a twitter fight with Neil deGrasse Tyson, which also gets Bill Nye involved.|
|257||1202||The Wedding Gift Wormhole||September 27, 2018||Mark Cendrowski||Stuart gets the nerve up to ask Denise out on a date, Leonard and Penny give Sheldon and Amy a strange wedding gift and Raj asks his father to find a wife for him.|
|258||1203||The Procreation Calculation||October 4, 2018||Mark Cendrowski||The Wolowitzes' life gets complicated when Stuart starts bringing his new girlfriend home. Also, Penny and Leonard talk about starting a family while Koothrappali explores an arranged marriage.|
|259||1204||The Tam Turbulence||October 11, 2018||Mark Cendrowski||When Sheldon won’t tell anyone why he's never mentioned Tam, his childhood best friend, Leonard takes matters into his own hands. Also, Bernadette and Penny take out Raj's fiancée, Anu, for dinner to get the skinny on her.|
|260||1205||The Planetarium Collision||October 18, 2018||Mark Cendrowski||When Amy doesn't have time to work on super-asymmetry, Sheldon goes to great lengths to ensure she's available to work with him even it if means accidentally sabotaging her career in the process. Also, Raj doesn't want Howard to join him in hosting a show at the planetarium.|
|261||1206||The Imitation Perturbation||October 25, 2018||Mark Cendrowski||When Wolowitz dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny's Halloween party. Also, Leonard is shocked that Penny doesn't remember their first kiss.|
|262||1207||The Grant Allocation Derivation||November 1, 2018||Mark Cendrowski||Leonard is caught between a rock and a hard place when he's responsible for distributing extra grant money. Also, Bernadette turns the backyard playhouse into a hideaway from her husband and kids.|
|263||1208||The Consummation Deviation||November 8, 2018||Mark Cendrowski||Sheldon tries to bond with Mr. Fowler, but when Wolowitz lures Mr. Fowler away with magic tricks, Sheldon has no choice but to bond with Mrs. Fowler. Also, Raj and Anu to get physical for the first time.|
|264||1209||The Citation Negation||November 15, 2018||Mark Cendrowski||Leonard researches citations for Sheldon and Amy's paper. He finds a Russian paper that basically discredits super-asymmetry. Bernadette tries to beat Howard and Raj at Fortnite, and recruits help from Denise.|
|265||1210||TBA||December, 2018||Mark Cendrowski||TBA|
|266||1211||TBA||December, 2018||Mark Cendrowski||TBA|
|267||1212||TBA||January, 2019||Mark Cendrowski||TBA|
|268||1213||TBA||January, 2019||Mark Cendrowski||TBA|
|269||1214||TBA||February, 2019||Mark Cendrowski||TBA|
|270||1215||TBA||February, 2019||Mark Cendrowski||TBA|
|271||1216||TBA||February, 2019||Mark Cendrowski||TBA|
|272||1217||TBA||February, 2019||Mark Cendrowski||TBA|
|273||1218||TBA||March, 2019||Mark Cendrowski||TBA|
|274||1219||TBA||March, 2019||Mark Cendrowski||TBA|
|275||1220||TBA||April, 2019||Mark Cendrowski||TBA|
|276||1221||TBA||April, 2019||Mark Cendrowski||TBA|
|277||1222||TBA||April, 2019||Mark Cendrowski||TBA|
|278||1223||TBA||May, 2019||Mark Cendrowski||TBA|
|279||1224||TBA||May, 2019||Mark Cendrowski||TBA - Series finale.|
- Amy's parents could return to appear again this season after they attended Sheldon and Amy's Wedding. It has been confirmed they will appear in an episode this season. They appeared in the premiere episode.
- Penny's father, Wyatt will make an appearance this season. He is appearing in the third episode. 
- Amy and Sheldon will start their first year as a married couple.
- Some of the gang could be moving by year's end though that has not been confirmed.
- Tam Nguyen had been confirmed to appear in an episode this season (episode four), and Sheldon revealed the reason he has not been throughout the first 11 seasons. He is played by Robert Wu.
- Mary Cooper may return this season, but this has not been confirmed.
- Sheldon and Amy's honeymoon was confirmed to be happening in the premiere episode.
- On August 22, 2018, CBS announced that Season 12 was going to be the final season.
- Neil deGrasse Tyson and Bill Nye both appeared in the premiere episode.
- Last call for The Big Bang Theory! Jim Parsons pulled the plug after declining a 50 million dollar deal.
- Bert Kibbler, V. M. Koothrappali, and Denise appeared in the second episode.
- Sheldon and Amy honeymooned in New York and at LEGOLAND.
- Stuart and Denise started dating in the second episode.
- Keith Carradine returned as Penny's father, Wyatt.
- Leonard and Penny discussed having children in the third episode.
- Bob Newhart returned in episode five as Professor Proton.
- Jerry O'Connell returned as Sheldon's brother George Cooper Jr. in episode four.
- President Siebert appeared in the fifth episode and will reappear in the seventh episode.
- This will be the final season, it is unknown how will they end it.
- Penny Hofstadter and Leonard Hofstadter decided not to have kids and decide to become a cool uncle and aunt to Howard and Bernadette's children. But they maybe they'll change their minds or have a surprise by season's end.
- Barry Kripke is reappearing in the seventh episode.
- Raj is set up in an arranged marriage to a woman named Anu. They become engaged in the third episode. It is unknown whether or not they will marry.
- Raj and Anu set a wedding date for Valentine's Day 2019.
- A crossover of sorts with Young Sheldon will happen in December, as the younger versions of Sheldon (Iain Armitage), Georgie (Montana Jordan), and their father George Sr. (Lance Barber) will guest star in an upcoming episode. The nature of their appearance is currently unknown, though the most likely explanation is that it will be one or more flashback sequences filmed specifically for this episode.
- ↑ http://www.nme.com/news/tv/big-bang-theory-renewed-two-seasons-2019-2024066
- ↑ https://www.spoilertv.com/2018/08/the-big-bang-theory-ending-after-season.html
- ↑ https://twitter.com/bigbangtheory/status/1020370544904978432
- ↑ https://tvline.com/2018/09/04/the-big-bang-theory-keith-carradine-season-12-wyatt-return/
- ↑ https://deadline.com/2018/11/the-big-bang-theory-iain-armitage-lance-barber-montana-jordan-to-appear-in-young-sheldon-crossover-1202501902/