Justin is an impressionist and voice actor from Los Angeles. In 2012, Justin appeared in an episode of All The Wrong Notes. In 2014, he played Sterling in the pilot of Semi-Famous, a drunk bar patron in an episode of Partners and Jerry Dowdell in Scorpion. In 2015 he played both a character named Justin in the short What If Catcalls Were Cheeseburgers? and Sefiullah in the Video Short Before and After Uber. Between 2012 & 2015 he played an announcer in TV Series Zombie Whisperer.
In 2016 Justin played both Alexander Haig in Operation Chromite and appeared in an episode of Standup and Away! with Brian Regan.
In 2019, he provided the voice of Tuffnut Thorston in How to Train Your Dragon: The Hidden World and its accompanying TV Short How to Train Your Dragon: Homecoming. Additionally in 2019, he voiced Rob in the Short Flyby and a Komodo Dragon in an episode of Disney's Doc McStuffins. In 2022 prior to auditioning for AGT, he was cast as James in TV Series Bee Man.
Justin Rupple's audition in Episode 1704 consisted of performing a routine about doing celebrity impersonations while impersonating the voices of Mark Wahlberg, Ryan Reynolds, Liam Neeson and others. All 4 judges voted "Yes", sending him to the next round.