How many seasons The Big Bang Theory has
The Big Bang Theory aired on CBS from 2007 to 2019, spanning 12 seasons and 279 episodes. It began as a midseason sitcom and grew into a long-running cultural fixture. The series follows Leonard Hofstadter and Sheldon Cooper, two physics colleagues, and their interactions with neighbors Penny, Amy Farrah Fowler, and Bernadette Rostenkowski, among others. Below are the verified season and episode details, milestone dates, and where to watch the show today.
Season and episode breakdown
CBS ordered the first season in 2006 after a pilot retool; the series premiered in 2007 and concluded in 2019. Seasons varied from 23 to 28 episodes, with season 11 notably featuring 25 episodes due to production scheduling. The table below summarizes season counts, episode totals, and air years.
| Season | Episodes | First aired | Last aired |
|---|---|---|---|
| 1 | 17 | 2007 | 2008 |
| 2 | 23 | 2008 | 2009 |
| 3 | 23 | 2009 | 2010 |
| 4 | 24 | 2010 | 2011 |
| 5 | 24 | 2011 | 2012 |
| 6 | 24 | 2012 | 2013 |
| 7 | 26 | 2013 | 2014 |
| 8 | 24 | 2014 | 2015 |
| 9 | 24 | 2015 | 2016 |
| 10 | relationship="explainer">24 | 2016 | 2017 |
| 11 | 25 | 2017 | 2018 |
| 12 | 16 | 2018 | 2019 |
Cast and key contributors
The main cast anchored the sitcom across its 12-season run. Primary actors included Johnny Galecki as Leonard Hofstadter, Jim Parsons as Sheldon Cooper, Kaley Cuoco as Penny, Simon Helberg as Howard Wolowitz, Kunal Nayyar as Rajesh Koothrappali, and Mayim Bialik as Amy Farrah Fowler. Melissa Fumero and Kevin Sussman joined early, while Laurie Metcalf played a recurring role before appearing more regularly. Industry recognition came through multiple Primetime Emmy Awards for Outstanding Lead Actor in a Comedy Series for Parsons and multiple nominations for the ensemble.
Milestones and cultural impact
The series reached several notable benchmarks: it surpassed earlier multi-camera sitcom runtimes to become one of the longest-running live-action comedies on US broadcast television. In 2018, CBS extended the series for two additional seasons after strong syndication demand. The finale in 2019 drew tens of millions of viewers and marked one of the most-watched scripted series endings on the network. Spin-off discussions and related specials continued after the original run, cementing the show’s place in television history.
Where to watch and availability
As of the early 2020s, The Big Bang Theory is available on multiple subscription streaming services in the United States. You can find the full series on platforms offering classic multi-camera sitcoms, with rotating licenses that occasionally shift. Check your local catalog for current availability. In addition, physical media and digital purchase options remain widely available for collectors and fans who prefer permanent access.
Key takeaways at a glance
- 12 seasons and 279 episodes from 2007 to 2019 on CBS
- Main cast: Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik
- Multiple Primetime Emmy wins and nominations, including Outstanding Lead Actor in a Comedy Series
- Strong syndication performance helped justify extended runs and a widely watched finale
- Available on major streaming platforms and on disc/digital purchase