Madeleine Martin is the voice actress for Fionna in Adventure Time. She is best known for playing the character Rebecca "Becca" Moody on Showtime comedy-drama Californication. Martin has had prior voice acting experience in the Playhouse Disney show JoJo's Circus, in which she played the titular character. She has also appeared on the CBS thriller, Criminal Minds. She is a student at the School of American Ballet.