Flynn is managed by PCM International. He moved to Los Angeles to pursue an acting career. Before making his acting debut, Flynn worked with director, Jake Scott in 2013, by appearing in a Taco Bell commercial . In the same year, he made his acting debut when he landed the role of Liret in a short movie called 80 in 10. He did a campaign of "Silk" for photographer Bryony Shearmur.
In February 2014, Flynn landed a guest role on the hit CBS television series, Hawaii Five-0, in an episode entitled, "Hoku Welowelo"; Flynn played the role of Nick Spitz, opposite actress Melanie Griffith. Flynn also co-produced his short movie called Solely. In August 2014, DAYS co-executive producer, Greg Meng confirmed to Soap Opera Digest that Billy Flynn has joined the cast of NBC soap opera Days of Our Lives, as a recast of Chad DiMera, which was previously played by actor Casey Deidrick. Flynn made his on-screen debut on September 12, 2014.