- All-Star Cast:
- As with all Ghibli films since 1997, several famous actors and comedians provide several roles in the film, such as Tomoko Yamaguchi, George Tokoro, Kazushige Nagashima, Yuki Amami, Tomoko Naraoka, and Kazuko Yoshiyuki. Rumi Hiiragi, who voiced Chihiro in Spirited Away, voices the young mother.
- While Disney has always been able to find a few famous actors to do the English dubs of Ghibli films and Kingdom Hearts, this movie seriously takes the cake. With a cast including Matt Damon, Tina Fey, Cate Blanchett, Liam Neeson, Betty White, Lily Tomlin, and Cloris Leachman.
- Approval of God: Hayao Miyazaki was impressed by the film's English dub.
- Children Voicing Children: Ponyo and Sosuke are voiced by actual young children.
- Doing It for the Art: Pretty much a given with Miyazaki films, but impressive even by his standards—no CGI was used during this film, at all.
- Image Source: Plucky Girl
- Promoted Fanboy: Fujimoto's English VA Liam Neeson was familiar with Miyazaki's works before he was cast.
- Reality Subtext: Miyazaki made Ponyo as a means of trying to reconcile with his estranged son (the one who directed Tales from Earthsea). Throughout the film, Sosuke and his father are separated.
- Real-Life Relative: Joe Hisaishi's daughter Mai sings vocals on several cues of the film's score. Mai even sang the image song "Rondo of the House of Sunflowers".
- So My Kids Can Watch: For the English dub, Megan Marshall, the daughter of the English version's executive producers Frank Marshall and Kathleen Kennedy, suggested that Frankie Jonas and Noah Cyrus should play Sosuke and Ponyo, respectively.
- Written for My Kids: A sad variant; as noted in Reality Subtext above, Miyazaki wrote the film with his own estranged son in mind.
- What Could Have Been: Miyazaki wanted to do a sequel to the film, however Ghibli producer Toshio Suzuki didn't want a sequel and suggested he do a film based off of famed plane engineer and designer Jiro Horikoshi instead, which he wasn't initially keen on at first, but eventually got behind it. While this did lead to the critically acclaimed The Wind Rises, one can't help but wonder what a Ponyo sequel could have look liked.
Trivia / Ponyo on the Cliff by the Sea