This CBS Sitcom Was the Biggest TV Show of 2015 — Were You Watching?

Amid a crowded TV landscape that included the likes of NCIS, The Walking Dead, Blue Bloods, and more, one hit CBS sitcom reigned supreme in 2015.

The Big Bang Theory, Chuck Lorre’s show about a group of socially awkward Caltech scientists who live in Pasadena, was the biggest show of 2015, a year that saw the second half of Season 8 and the beginning half of Season 9 broadcast on CBS.

Starring Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik, and Melissa Rauch, among others, The Big Bang Theory averaged q 7.1 rating and 21 million viewers in 2015, according to Nielsen viewership data. Those numbers made it the No. 1 scripted show of the year, beating out the likes of fellow CBS show NCIS (7.1 and 20.9 million), AMC’s hit series The Walking Dead (6.6 and 19.6 million), Fox’s Empire (6.0 and 17.7 million), and CBS’ NCIS: New Orleans (5.8 and 17.3 million).

Created by Lorre and Bill Prady, The Big Bang Theory starred Parsons as theoretical physicist Sheldon Cooper and Galecki as experimental physicist Leonard Hofstadter, CalTech scientists and roommates navigating social situations, including dating, alongside their across-the-hall neighbors and friends. The cast also featured Cuoco as pharmaceutical sales representative Penny Hofstadter, Nayyar as particle astrophysicist Rajesh Koothrappali, Bialik as neurobiologist Amy Farrah Fowler, and Helberg as aerospace engineer Howard Wolowitz.

The Big Bang Theory ran for 12 season and 279 episodes from 2007 until 2019, making it the longest-running multi-camera sitcom. During its run, the show became a massive hit, winning 10 Emmy Awards, cementing its place as one of the best sitcoms of all time, and earning an 81% critics score on Rotten Tomatoes.

The Big Bang Theory proved to be such a hit that even after the sitcom ended, its universe has lived on. A prequel series Young Sheldon, following the childhood days of boy genius Sheldon Cooper, ran for seven seasons from 2017 to 2024. That series itself spawned the spinoff Georgie & Mandy’s First Marriage, which follows newlyweds Georgie Cooper (Montana Jordan) and Mandy McAllister (Emily Osment) as they raise their daughter CeeCee in Texas. The show premiered in October 2024 and was renewed for a second season in February. Another spinoff, a direct sequel to the original Big Bang Theory, is in development at Warner Bros. Discovery’s Max.

Although The Big Bang Theory is no longer airing new episodes, fans can revisit the hit show on Max, where all 12 seasons are available to stream.