[4] Knight's first role with Disney was in an episode of Hannah Montana, playing Lilly’s boyfriend Lucas, in 2007.
[7] In 2009, Knight played the role of Chad Dylan Cooper, an egotistical and self-centered cast member of Mackenzie Falls and self-proclaimed Hollywood legend in Sonny with a Chance.
Knight made his film debut in 17 Again playing Alex O'Donnell, Matthew Perry/Zac Efron's son who was abused by his sister's boyfriend.
In 2010, Knight played teen heart-throb Christopher Wilde in the Disney Channel Original Movie Starstruck.
In 2012, Knight starred as Shane Seedwell in the action thriller film Transit co-starring Jim Caviezel and Elisabeth Rohm.
[16] In 2016, Knight guest-starred in two episodes of NBC series Crowded, where he played the love interest of Miranda Cosgrove's character.
In November 2014, Knight began dating actress Ayla Kell, whom he had met on the set of Melissa & Joey.