At six, his YouTube channel Iain Loves Theatre was pulling coverage from Playbill and CBS News. He'd started posting video reviews of Washington D.C. productions at three, talking about musicals with the authority of a seasoned critic. The clips went viral enough that a talent agent came calling. Within a few years, he was holding his own opposite Nicole Kidman, Reese Witherspoon, and Laura Dern in Big Little Lies, playing Ziggy Chapman with a grounded sensitivity that stood out in one of TV's most celebrated casts. CBS cast him as the lead in Young Sheldon before he'd turned ten.
Young Sheldon ran seven seasons, from 2017 to 2024, and he was in every episode. He's said wrapping it felt like losing 'basically half my life.' Post-finale, he's guesting on CBS's Ghosts (April 2026) playing a heightened version of himself in a poker scenario, which is either clever brand management or proof that TV won't let you escape your last show. He's been public about wanting action movies and dramas next, roles that couldn't be further from a nerdy Texas kid in the 1980s.
His family background is theatrical by design. His father is Broadway actor Euan Morton, his mother is theater producer Lee Armitage, and his godfather is Eric Schaeffer, director of Washington D.C.'s Signature Theatre. His grandfather is former U.S. Deputy Secretary of State Richard Armitage, which pairs a Tony-connected family tree with a national security pedigree in one household. The theater obsession stuck: in 2025, he was backstage at Shailene Woodley's Broadway run, not as a fan, but as a colleague.