It's been created by Chuck Lorre and Steve Molaro, the executive producers behind the original show.
Young Sheldon will star Iain Armitage as a nine-year-old Sheldon Cooper, one of the main characters in the hit show.
Jim Parsons, who plays Sheldon, will narrate the new show as the adult Sheldon.
Zoe Perry will take on the role of Sheldon's mother - the character is played by Zoe's real mother Laurie Metcalf in Big Bang Theory.
Jon Favreau, the man behind Iron Man and a recent re-make of The Jungle Book, will direct the first episode which has been written by Steve Molaro.
However, it's not yet been confirmed how long the Young Sheldon series will be.
Steve Molaro has previously spoken about the future Big Bang Theory, saying he expected it would end after season 10.
That has since been backed up by Kunal Nayyar, who plays Raj in the show.
Speaking ahead of the filming, he said: "Look, next season, as it stands on our contract, could be the last season of Big Bang Theory."
The show has now reached that point but, after picking up several TV Emmys and some of the highest biggest comedy ratings for years, it's thought CBS is considering commissioning more seasons.