Holt was born in Germantown, Tennessee, to Mark and Kim Holt. She has two siblings. At age three, her family moved to Nesbit, Mississippi, where she grew up after briefly living in Memphis, Tennessee. Growing up, she took gymnastics classes for seven years. In 2011, she moved to Los Angeles with her family.
Holt began her acting career in local theater productions. She started appearing in television commercials at the age of 10, for products including Hasbro, Kidz Bop 14, Mattel, Bratz dolls, Littlest Pet Shop, and Girl Gourmet. 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 left the show 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 outcast. The series ended on October 16, 2015, after two seasons. 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's next in line.
In November 2014, Holt joined the cast of the drama Same Kind of Different as Me, directed by Michael Carney and also starring Greg Kinnear and Renée Zellweger, who play her character's parents in the film. Paramount has scheduled the film for release on February 3, 2017. In November 2015, it was announced that Holt had been cast in a lead role in the indie comedy Class Rank, directed by Eric Stoltz. In May 2016, it was announced that she would star alongside Ross Lynch in Status Update, directed by Scott Speer, with filming to commence the following month in Vancouver.
Holt recorded three songs for the 2012 film Girl vs. Monster, in which she also starred. The songs were featured on the compilation Make Your Mark: Ultimate Playlist. She won a 2013 Radio Disney Music Award for Best Crush Song for "Had Me @ Hello", which was featured in the film. She also recorded a cover version of "Winter Wonderland" for the 2012 Disney Channel Holiday Playlist album. Her song "Carry On" was the theme song for the 2014 Disneynature film Bears.
In October 2014, Holt signed a record deal with Hollywood Records. Her debut single, "Phoenix", came out on May 13, 2016. The music video was released on June 23, 2016. Olivia, her debut EP, was released on July 15, 2016.
In 2013, Holt partnered with mobile gaming system maker PlayMG as a spokesperson and part owner, to help the company develop new versions of its app-based games. She was announced as a brand ambassador for Neutrogena in March 2016.
|2009||Black & Blue||Claire|
|2014||Tinker Bell and the Legend of the NeverBeast||Morgan||Voice|
|2016||Class Rank||Veronica Krauss||Post-production|
|2016||The Standoff||Amy Roberts||Post-production|
|2017||Same Kind of Different as Me||Regan Hall||Post-production|
|2017||Status Update||Dani McKenzie||In production|
|2010||Disney XD's My Life||Herself||Disney XD documentary|
|2011–15||Kickin' It||Kim||Main role (Season 1–3)|
Recurring role (Season 4)
|2012||Girl vs. Monster||Skylar Lewis||Television film|
|2013||Shake It Up||Young Georgia||"My Bitter Sweet 16 It Up" (Season 3, Episode 22)|
|2014–15||I Didn't Do It||Lindy Watson||Lead role|
|2014-16||Best Friend's Brother||Vanessa Davenport||Recurring|
|2015||Ultimate Spider-Man||Petra Parker/Spider-Girl||"The Spider-Verse: Part 1" (Season 3, Episode 9)|
"The Spider-Verse: Part 4" (Season 3, Episode 12)
|2015||Dog with a Blog||Wacky Jackie||"Stan Gets Married" (Season 3, Episode 13)|
|2015||Penn Zero: Part-Time Hero||Amber||"Amber" (Season 1, Episode 12)|
"Save the Worlds" (Season 1, Episode 21)
|2016||The Evermoor Chronicles||Valentina||"Valentina" (Season 1, Episode 17)|
|2011||KARtv||Guest Host||"Jingle Bell Rock by Rockboard Scooters" (Season 1, Episode 3)|
|2014||"Carry On"||Non-album singles|
|"Time of Our Lives"|
|2014||"Carry On"||Jonathan Craven, Darren Craig and Jeff Nicholas|
|"Do You Want to Build a Snowman?"||Harry Perry III||Among Disney Channel Circle of Stars|
Awards and nominations
|2013||Radio Disney Music Awards||Best Crush Song||"Had Me @ Hello"||Won|||
|Shorty Awards||Best Actress||Kickin' It||Nominated|||