Frankie is the son of Denise and Paul Kevin Jonas and the younger brother of Kevin Jonas, Joe Jonas and Nick Jonas. Jonas is sometimes referred to as the "Bonus Jonas". and "Frank the Tank".
In 2009, Jonas lent his voice to a Japanese animated film, Hayao Miyazaki's "Ponyo", which was released in American theaters on August 14, 2009. He played Sōsuke, a character who is befriended by a juvenile fish named Ponyo (voiced by Noah Cyrus), who wants to become a human girl. They also both sing the theme song to the movie.
He appeared as a recurring character in the Disney Channel Original Series, Jonas L.A. for which he won the award for "Choice Breakout TV Star Male" at the 2009 Teen Choice Awards.