Barbie: Mermaidia or Barbie Fairytopia: Mermaidia is a 2006 direct-to-video computer-animated film directed by Walter P. Martishius and William Lau, and produced by Mainframe Entertainment.

In this animated follow-up to Fairytopia, Elina (played by Barbie) enlists the help of a mermaid, Nori, to save her friend Nalu, a merman prince who has been captured by the wicked Laverna.