The Big Bang Theory season 12

The twelfth and final season of the American television sitcom The Big Bang Theory aired on CBS from September 24, 2018 to May 16, 2019. The series returned to its regular Thursday night time slot on September 27, 2018.

Production
In March 2017, CBS renewed the series for two more seasons, bringing its total to twelve and securing that the series would run through the 2018–19 television season. On August 22, 2018, CBS and Warner Bros. Television officially announced that the twelfth season would be the series' last. This stemmed from Jim Parsons' decision to leave the series at the end of season twelve if the show were to have been renewed for a thirteenth season. The series concluded with an hour-long finale consisting of two back-to-back episodes on May 16, 2019.

Main cast

 * Johnny Galecki as Dr. Leonard Hofstadter
 * Jim Parsons as Dr. Sheldon Cooper
 * Kaley Cuoco as Penny Hofstadter
 * Simon Helberg as Howard Wolowitz
 * Kunal Nayyar as Dr. Rajesh "Raj" Koothrappali
 * Mayim Bialik as Dr. Amy Farrah Fowler
 * Melissa Rauch as Dr. Bernadette Rostenkowski-Wolowitz
 * Kevin Sussman as Stuart Bloom

Recurring cast

 * Christine Baranski as Dr. Beverly Hofstadter
 * Brian Posehn as Dr. Bertram "Bert" Kibbler
 * Brian George as Dr. V.M. Koothrappali
 * Lauren Lapkus as Denise
 * Keith Carradine as Wyatt
 * Rati Gupta as Anu
 * Bob Newhart as Dr. Arthur Jeffries/Professor Proton
 * Joshua Malina as President Siebert
 * John Ross Bowie as Dr. Barry Kripke
 * Brian Thomas Smith as Zack Johnson
 * Lindsey Kraft as Marissa Johnson
 * Kal Penn as Dr. Kevin Campbell
 * Sean Astin as Dr. Greg Pemberton

Guest cast

 * Teller as Larry Fowler
 * Kathy Bates as Mrs. Fowler
 * Neil deGrasse Tyson as himself
 * Bill Nye as himself
 * Jerry O'Connell as George Cooper Jr.
 * Robert Wu as Tam Nguyen
 * Maribeth Monroe as Dr. Lee
 * Iain Armitage as Young Sheldon
 * Lance Barber as George Cooper Sr.
 * Montana Jordan as Young George Cooper Jr.
 * Andy Daly as Nathan
 * William Shatner as himself
 * Wil Wheaton as himself
 * Kevin Smith as himself
 * Kareem Abdul-Jabbar as himself
 * Joe Manganiello as himself
 * Ellen DeGeneres as herself
 * George Smoot as himself
 * Kip Thorne as himself
 * Frances H. Arnold as herself
 * Regina King as Janine Davis
 * Todd Giebenhain as Mitch
 * Sarah Michelle Gellar as herself

Special
A retrospective, Unraveling the Mystery: A Big Bang Farewell, hosted by Johnny Galecki and Kaley Cuoco, aired at 9:30 P.M. ET/PT, the night of the finale, following the season two finale of Young Sheldon, and the series finale of The Big Bang Theory. The special was also included on the DVD and Blu-Ray releases of the season.