Iain Armitage, 17, Has Had A Big Transformation Since Young Sheldon Ended
"Young Sheldon" fans were first introduced to Iain Armitage back in 2017, when the actor was only nine years old, but a lot has changed since then. The show has wrapped, and just as the "Young Sheldon" cast has transformed more generally, while we wouldn't say young Sheldon Cooper isn't young anymore, he's certainly grown up a lot. In fact, many social media users have been blown away by his transformation.
Okay, so a lot of the social media response stemmed from the specific pose Armitage used in one Instagram post in particular. With a mock serious expression and antique glasses, Armitage was kind of giving old school Hugh Grant vibes (though some Instagram users pointed out that he looked an awful lot like Tom Cruise when he was younger, and others still mused that he reminded them of a young Pierce Brosnan). That said, there was no mistaking who the young man was. Au contraire, his comments section was filled with fans who were blown away by how grown up he looked. "You're growing up too fast ... just the other day you went to school in a bow tie," joked one Instagram user, referencing the iconic first episode of the "Big Bang Theory" spinoff. "OH MY G-D IS THAT MY SOFT KITTY WARM KITTY LITTLE BALL OF FUR?" quipped another.
Amid all the musings on who he looked most like and the fact that he was nearing adulthood, many also quipped that Armitage's transformation was making them feel older — and TBH, same.
Iain Armitage still adores his 'Young Sheldon' co-stars
One thing Iain Armitage that hasn't changed over time is his love for his "Young Sheldon" co-stars. In fact, in the time since their show wrapped, when the actor has seen his former colleagues, he's taken to social media to gush about the experience.
A few months after "Young Sheldon" wrapped for good, Armitage shared on Instagram that he and his on-screen mom Zoe Perry had hung out in Washington, D.C. "Such a happy day for me! I got to reunite with my TV mama, Zoe Perry!!!" he wrote in the caption, sharing that they'd been invited to see the White House's Christmas decorations together. A few months after that, he also shared that he'd hung out with his on-screen professor, Ed Begley Jr. "The days I got to spend on the set of 'Young Sheldon' working with Ed and Wally Shawn were some of my very favorite days. Getting to learn from people who are so experienced is great, but they are also such good humans," he wrote, adding a sweet shout-out to Begley's autobiography.
It's worth noting that even as he's gotten older, Armitage has also continued to lavish praise on his colleagues outside of "Young Sheldon." In the wake of Hollywood icon Robert Redford's passing in September 2025, Armitage penned a very touching tribute to his "Our Souls at Night" co-star, recounting how kind the veteran actor had been to him. Armitage has also issued sweet shout-outs to his "Big Little Lies" mom, Shailene Woodley, and the fellow actors he worked with when he became a tour guide for Warner Bros. Studio Tour (he'd been invited to do so the day "Young Sheldon" ended). One thing's for sure: Armitage may have transformed into a young man, but he's certainly just as polite as he's always been.