When Sosuke, a young boy who lives on a clifftop overlooking the sea, rescues a stranded goldfish named Ponyo, he discovers more than he bargained for. Ponyo is a curious, energetic young creature who yearns to be human, but even as she causes chaos around the house, her father, a powerful sorcerer, schemes to return Ponyo to the sea.
| Ponyo (voice) | Yuria Kozuki |
| Sosuke (voice) | Hiroki Doi |
| Fujimoto (voice) | George Tokoro |
| Risa (voice) | Tomoko Yamaguchi |
| Gran Mamare (voice) | Yuki Amami |
| Koichi (voice) | Kazushige Nagashima |
| Ponyo's Sister (voice) | Akiko Yano |
| Anchorman (voice) | Shin'ichi Hatori |
| Kayo (voice) | Tokie Hidari |
| Young Mother (voice) | Rumi Hiiragi |
| Yoshie (voice) | Tomoko Naraoka |
| Toki (voice) | Kazuko Yoshiyuki |
| Kumiko (voice) | Eimi Hiraoka |
| Karen (voice) | Nozomi Ōhashi |
| Noriko (voice) | Akiko Takeguchi |
| (voice) | Eiko Kanazawa |
| (voice) | Akihiko Ishizumi |
| (voice) | Tomie Kataoka |
| (voice) | Shirou Saitou |
| (voice) | Mutsumi Sasaki |
| (voice) | Keiko Tsukamoto |
| (voice) | Ikuko Yamamoto |
| (voice) | Michiko Yamamoto |
| (voice) | Yoshie Yamamoto |
| (voice) | Yusuke Tezuka |
