Barbie stars as Merliah, a surfer who learns a shocking secret: she's a mermaid! She and her dolphin friend set out for an undersea adventure to rescue her mother, the queen of Oceana.
| Actor | Role |
|---|---|
 Kelly SheridanMerliah (voice) | Merliah (voice) |
 Kathleen BarrEris / Snouts (voice) | Eris / Snouts (voice) |
 Tabitha St. GermainZuma / Deanne (voice) | Zuma / Deanne (voice) |
 Peter MelSurf Announcer (voice) | Surf Announcer (voice) |
 Nakia BurriseFallon (voice) | Fallon (voice) |
 Maryke HendrikseHadley (voice) | Hadley (voice) |
 Emma PiersonKayla (voice) | Kayla (voice) |
 Ciara JansonXylie (voice) | Xylie (voice) |
 Garry ChalkBreak (voice) | Break (voice) |
 Nicole OliverCalissa (voice) | Calissa (voice) |
 Alistair AbellRemo / Pufferazzi (voice) | Remo / Pufferazzi (voice) |
 Andrea LibmanDee (voice) | Dee (voice) |
 Shannon Chan-KentDeandra (voice) | Deandra (voice) |
 Ellen KennedyLipstick Fish / Syrenka (voice) | Lipstick Fish / Syrenka (voice) |
 Scott McNeilSyrenka's Pet Fish (voice) | Syrenka's Pet Fish (voice) |
 Melissa LyonsMerliah (singing voice) | Merliah (singing voice) |
 Alex FerrisDreamfish (voice) | Dreamfish (voice) |