Young Sheldon's Iain Armitage Got His Start On Law & Order: SVU

Appearing in an episode of "Law & Order" is a working actor's rite of passage. Only a rarified few, however, can say they achieved that claim to fame under the age of 10. For "Young Sheldon" star Iain Armitage, "Law & Order: SVU" marked the beginning of his acting career.

In 2017, Armitage made his acting debut in a Season 18 episode of "SVU." In "Chasing Theo," Armitage plays the titular Theo, a 6-year-old boy who goes missing while his mother Nadine (Rachelle Lefevre) throws a party down the hall from their apartment. There are several suspects, including some unsavory characters Nadine fraternizes with, including a cokehead ex-boyfriend. Also disconcerting is the contentious relationship between Theo's divorced parents; Nadine loves to entertain, so much so that Theo regularly sleeps in noise-canceling headphones. His other mother, Fran (Zoe McLellan), is such a workaholic that she didn't have time to formally adopt Theo, though she longs to attain custody.

The culprit ends up being Theo's nanny, Gloria, who kidnaps the boy for fear that he's being neglected to the point of endangerment. Armitage's Theo is necessarily absent for most of the hour, but his appearances bookend the episode, including an emotional performance at the end where he longs to stay with Gloria.

While this role was a big one for Armitage, it wouldn't be the only one he landed that year. 2017 proved to be the big bang, so to speak, of his career.

Iain Armitage may not have acted professionally until 2017, but he unofficially entered the industry as a toddler when he became known for his charming theater reviews. His popular YouTube account, Iain Loves Theater, blossomed into a TV career, beginning with a 2016 appearance on "Little Big Shots" as a guest judge. Prior to that, he even accidentally stumbled onto an episode of "Impractical Jokers."

In 2017, Armitage's career blew up. In addition to making his acting debut on "SVU," he appeared in three films: "The Glass Castle," "Our Souls at Night," and "I'm Not Here." 2017 was also the year he secured the roles for which he is best known. That year he began acting in "Big Little Lies" and "Young Sheldon." For his role as Ziggy in the HBO drama, he earned a National Film and Television Awards nomination for best newcomer. His debut season as Sheldon Cooper netted a few nominations as well, including at the Young Artist Awards and Teen Choice Awards.

Armitage's Season 18 "Law & Order" gig wasn't the first time he had been on the "SVU" set. In 2015, long before his acting aspirations took off, Armitage visited his godfather Raúl Esparza on the set of "SVU," where he met Mariska Hargitay for the first time.