Iain Armitage has gone from Young Sheldon to Adolescent Sheldon, as the 17-year-old actor surprised fans with a recent selfie showing just how much he’s grown.
Taking to his Instagram page on Sunday (September 28), Armitage posted two photos wearing a black fleece jacket and a pair of old school round spectacles. “Incomprehensible drip from 1823,” he captioned the post.
Fans flooded the comments with shock at how much he has grown since starring in The Big Bang Theory spinoff. Armitage was just 8 years old when Young Sheldon debuted in 2017 and 15 when the show wrapped up its run in May 2024.
“Oh sheldon! you have grown up so fast!” wrote one commenter.
“When did he became so grown😭,” said another.
“Omg i don’t see young shelly at all!! Looking good ian❤️,” another added.
Another quipped, “Who gave such sophisticated glasses to sheldon.”
“Our young sheldon is not so young anymore,” said one user.
“You’re growing up too fast 🤧 just the other day you went to school in a bow tie,” said another, referencing Armitage’s iconic look from the hit CBS sitcom.
Michael Desmond/Warner Bros.
“Omg you growing too fast!!! 💨 slow down kid 😌🩷,” added another.
Another added, “He was an adorable looking child and now a very cute young man. My wish is that he remains true and good to himself.”
“Sir we aren’t ready for this yet! 😳😩😩😩,” one fan joked.
Others pointed out how he looked like a young Tom Cruise. “😱😱Tom Cruise son??? I can’t believe how similar u are!!!” said one commenter.

Iain Armitage Instagram; Buena Vista/courtesy Everett Collection
“Young Tom Cruise! Not Sheldon,” another added.
“The next tom cruise,” another wrote.
Another said, “Could also pass for a young Tom Cruise or his young brother in a movie!!”
After wrapping up Young Sheldon in May 2024, Armitage has been taking a break from acting to spend time with his family and focus on his studies. He has also been working on obtaining a student pilot’s license.
“I hopefully will get my private [pilot’s license] when I’m 17,” he told People last October. “I’ve been having a bunch of fun flying while I’m here in L.A.”