Stewart-Jarrett made his professional stage debut with a number of roles in Brixton Stories at the Lyric, Hammersmith, and has also appeared on stage in The History Boys at the National Theatre. In 2012, he appeared in the revival of Pitchfork Disney. In 2009, he joined the cast of Misfits as Curtis Donovan. In 2012, he was the last remaining original Misfits cast member on the show, until he was written out during the fourth series. He starred in the conspiracy thriller series Utopia. He also appeared in a music video by Years&Years called "real" released in 2014.