Possessing skills in gymnastics, Holt was cast in Disney XD's martial arts comedy Kickin' It, which premiered on June 13, 2011. She played the role of Kim in the series, as a main character in seasons 1–3, and as a special guest on three episodes in season 4. She starred in the 2012 Disney Channel Original Movie Girl vs. Monster, playing the lead character Skylar Lewis, a teenager who discovers that her family have long worked as monster hunters, and she is next in line. She left Kickin' It as a regular after season 3 to star in the Disney Channel half-hour comedy series I Didn't Do It, which premiered on January 17, 2014. The series follows five friends, including Holt's character, Lindy Watson, a nerdy, athletic, social outcast. The series ended on October 16, 2015, after two seasons. In January 2017, Holt was cast as Tandy Bowen / Dagger, one of the lead characters in the Freeform and Marvel Comics television series Cloak & Dagger. The series premiered in June 2018 and ran for two seasons until May 2019, after which it was canceled. Holt, along with her Cloak & Dagger co-star Aubrey Joseph, returned to voice their respective characters on the Disney XD animated series Spider-Man and are set to reprise their roles for a crossover episode in the third season of Marvel's Runaways.