Season 11 of Big Bang Theory will begin airing on CBS in mid-September 2017. Season 12 of Big Bang Theory will begin airing on CBS in mid-September 2018. Season 11 will air up to 24-episodes until early-May 2018 and Season 12 will air up to 24-episodes until early-May 2019, respectively.
As of 2017, Big Bang Theory airs every Thursday night at 8pm EST. In Syndication, since May 2010, Big Bang Theory has aired several episodes on TBS on Wednesdays, Thursdays, and Saturdays. In Canada, syndication rights to the series The Big Bang Theory belong to The Comedy Network, whereas in the United States, syndication rights belong exclusively to TBS.
In early November 2017, a Big Bang Theory spin-off series will premiere after an episode of Season 11. Called "Young Sheldon," the series will follow a little-boy Sheldon Cooper from a first person point-of-view camera and will feature actress Laurie Metcalf, best known as "Jackie" from ABC's Roseanne, but also Sheldon's mother on the The Big Bang Theory, in the role of little Sheldon's mother. Jim Parsons will voice the adult Sheldon, as the narrator of the series for CBS. Season 11 of Big Bang Theory will feature the usual cast of Sheldon, Leonard, Howard, Penny, Raj, Bernadette, and Stuart and will hit streaming services in the UK and other European countries in September 2018, although episodes of Season 11 of Big Bang Theory will be available on the CBS All Access streaming service as well.