Duty began auditioning for roles in Los Angeles after he was discovered at a showcase performance at the Young Actors Studio in Dallas, Texas by Hollywood talent agent, Cindy Osbrink and she invited him to come to California to audition for pilot season.  He has appeared in numerous national commercials for McDonald's, Wal-Mart, Pizza Hut, and Mattel.

In 2007, after several appearances in comedy sketches on The Tonight Show with Jay Leno, Duty landed his first featured role as Michael in the Lifetime television movie, Christmas in Paradise. Over the next two years, he appeared in guest-starring roles on Cold Case and The Jay Leno Show, as well as a co-starring role in the popular web series Ctrl.

In 2009, Duty landed his first feature film role in the suspense thriller, 2:13, as well as feature film roles in the horror film, Forget Me Not, the comedy film, Crazy on the Outside, and the Bollywood film, My Name Is Khan. In the spring of 2010, Duty gained popular notoriety in the role of "Young Jacob" on the hit TV series Lost, although no one, including Duty himself, knew who his character was until nearly the final episode of the series. He was billed simply as "Teenage Boy."

In the fall of 2010, Duty landed a co-starring role on the Disney Channel original series Shake It Up! as the flamboyant dancer/fashion designer, Gunther Hessenheffer alongside Caroline Sunshine as his twin sister, Tinka. The glitzy brother/sister duo of Gunther and Tinka is said to be inspired by Ryan and Sharpay Evans of Disney's High School Musical franchise. While finding some aspects of the show formulaic, People Magazine critic, Tom Gliatto expressed appreciation for the comedic twosome's work on the series, writing - "Shake It Up doesn't shake up the kidcom formula, but it has something more than the usual shiny-sparkly cuteness... The best performances are from Caroline Sunshine and Kenton Duty as an overbearing brother-and-sister act from abroad named Tinka and Gunther. They're like High School Musical's Sharpay split in two and speaking in an unplaceable accent."

On June 4, 2012, it was announced that Duty would no longer be a regular on Shake It Up, but would possibly return in a recurring capacity much like co-star Caroline Sunshine during the first season, though, he did not return at all. Not long after his departure from Shake It Up, Duty began work on the films Contest, Silver Bells and the short, Murphy.

After a brief stint in the musical group Invasion, Duty moved on to developing his solo music career. In May 2013, he released the lyric video for his first single, titled "Teenage Summer Nights."

Duty currently lives in Los Angeles with his parents and two younger twin sisters. Duty loves animals and dreamed of becoming a veterinarian before beginning his acting career. He has had a pet guinea pig named "Peanut", and has a horse named "Prince" that he keeps on his grandmother's property in Texas. Duty's hobbies include baking, cooking, spending time with his friends, and horseback riding. He also enjoys singing, playing guitar and songwriting. Before beginning work on the TV series Shake It Up!, Duty played guitar and sang in the band KGMC Gigmasters with Braeden Lemasters and fellow Lost co-star Dylan Minnette. Having no dance experience prior to his role on Shake It Up, Duty began taking private lessons in his free time to develop his dance skills.

When he isn't working, Duty involves himself with charitable causes including the Disney's Friends for Change initiative, which benefits environmental charities through the Disney Worldwide Conservation Fund, the Starlight Children's Foundation, which is dedicated to improving the quality of life for children with chronic and life-threatening medical conditions, UCLA Mattel Children’s Hospital, which is dedicated to researching and treating pediatric diseases, the Cystic Fibrosis Foundation, which is dedicated to improving the quality of life for those living with cystic fibrosis, and St. Jude Children's Hospital, which is dedicated to providing treatment to children with cancer and other catastrophic illnesses. He is also involved with the Food Allergy and Anaphylaxis Network (FAAN). FAAN is a non-profit organization that provides information, programs and resources about food allergies and anaphylaxis.

In addition to his charity work, Duty has been an outspoken voice against school bullying. In May 2011, he was named one of Dream Magazine's "Top 16 Under 16" and, when asked about the problem of bullying and cyber-bullying, Duty told the magazine - "You know, I have been bullied. It is always an awkward and difficult situation to be in. A couple of things to try when being bullied is to avoid the bully as much as possible, try using humor against the bully, have a sense of confidence... Hold your head up and look everyone in the eyes."