Iain Armitage was only nine years old when “Young Sheldon” premiered in September 2017, but that wasn’t his first time in front of the camera since he was on YouTube at age 4.

He made his TV debut in “Impractical Jokers” and then was on “Law & Order: Special Victims Unit,” and a few indie films. He starred in “Big Little Lies” and does voiceover work.

Barber has had a successful career as a guest-starring TV actor. He even appeared in an episode of “The Big Bang Theory” as a bully named Jimmy Speckerman.

He has also appeared in “ER,” “Gilmore Girls,” and “Monk” and had a recurring role as Maureen’s sleazeball brother, Bill Ponderosa, in "It's Always Sunny in Philadelphia."

Perry started her TV career in the 1990s when she starred in two episodes of “Roseanne” as a younger version of Jackie Harris (played by her real-life mother, Laurie Metcalf.)

She was in an episode of “Law & Order: Criminal Intent,” “Cold Case,” “Deception,” and “Conviction.” Before “Young Sheldon,” she was in nine episodes of “Scandal.”

“Young Sheldon” enlisted ‘80s icon Annie Potts to play Meemaw, so may recognize her from films like “Jumpin’ Jack Flash,” “Ghostbusters,” and “Pretty In Pink.”

She has appeared in many TV shows, including “Any Day Now,” "Law & Order: SVU," and “Joan of Arcadia.” She also lent her voice to Bo Peep in the "Toy Story" franchise.

Aside from "Young Sheldon" and a single flashback episode of "The Big Bang Theory," Jordan only has one other IMDB acting credit to his name.

In 2018, he starred alongside Josh Brolin in the Netflix film “The Legacy of a Whitetail Deer House.”