Young Sheldon isn’t so young anymore.
Iain Armitage, who played the titular boy genius on The Big Bang Theory spinoff prequel series, turns 17 on July 15.
The actor has been a TV star since Young Sheldon premiered in 2017, but before the sitcom, he started off as a novice theater critic. Iain was part of the Young Sheldon cast for seven seasons, from beginning to end until it wrapped up in 2024.
“I’m sure it seems like hard work, but I’ve been so lucky. It’s the easiest, most fun job in the world,” the actor told PEOPLE in October 2024 when reflecting onYoung Sheldon ending. “I get to play for a living, and I feel so honored and lucky to get to do that.”
In honor of Iain turning 17, take a look back at the actor’s life in photos, from attending his first Broadway show to his time on Young Sheldon and becoming a pilot.
Iain Armitage’s First Broadway Show
Iain is a dedicated theater fan, so much so that his first job wasn’t acting, but a theater reviewer.
His first time seeing a show on Broadway was in May 2012 when he attended the musical, Leap of Faith, based on the 1992 movie starring Steve Martin, according to an Instagram post.
Iain has since attended many Broadway productions over the years, supporting friends and former costars like Jim Parsons and Shailene Woodley.
Iain Armitage’s First Time at the Tony Awards
Iain’s love for theater eventually took him to the Tony Awards in 2016, where he was a correspondent on the red carpet.
During theater’s biggest night, Iain interviewed celebrities like Glenn Close, Gloria Estefan, Chita Rivera and more.
Iain Armitage’s First TV Role
Before Young Sheldon, Iain made his acting debut in a January 2017 episode of Law & Order: Special Victims Unit.
In the episode “Chasing Theo,” he played Theo Lachere, a 6-year-old boy who gets kidnapped.
Shortly after, a photo of him and series star Mariska Hargitay on set was shared on Instagram to commemorate the exciting moment, adding that he was “honored” to be on Law & Order: SVU.
Iain Armitage’s First Appearance on ‘Big Little Lies’
A few weeks after appearing on Law & Order: SVU, Iain first portrayed Ziggy Chapman, the son of Jane (Shailene Woodley), on the HBO hit series Big Little Lies in February 2017. He would go on to star in both seasons of the drama.
In December 2024, he reunited with Shailene and saw her Broadway debut in the play Cult of Love.
“When I was 7 I got cast in Big Little Lies,” Iain captioned an Instagram post of him and his former on-screen mom. “Before we headed to LA to begin filming, I had a FaceTime call with Shailene and I asked her what it would all be like.”
He continued, “She assured me that it would be fun, ‘like playing’ and wow, she was so right. I’m certain that the joy we had on Big Little Lies is the reason I stayed with acting.”
Iain Armitage Presents at the Emmy Awards with Jim Parsons
While his work on Big Little Lies aired on HBO, Iain was cast as the titular character on the spinoff prequel in March 2017, per Deadline.
Jim Parsons played Sheldon Cooper on The Big Bang Theory, and Iain helped showcase the character’s roots on Young Sheldon.
A week before Iain’s debut on the series in September 2017, Iain and Jim presented together at the 69th Annual Primetime Emmy Awards.
