Rebellious 16-year-old mermaid Ariel (Jodi Benson), daughter of King Triton, has an obbession with the human world. On one of her swims to the land, with her best-friend Flounder, she falls for a human prince. Quarelling with King Triton, her father, about her new forbidden love, Ariel then decides to make a dangerous deal with the sea witch Ursula (Pat Carroll) to become human for three days. Naive to Ursla's ulterior evil motives, Ariel consents. But when plans go awry for the star-crossed lovers, the king must make the ultimate sacrifice for his daughter.