When Nobita goes diving with Doraemon, a mermaid named Sophia comes close to him and they all befriend her. When they proceed towards her kingdom, they encounter a fight between two opposing tribes.
Unfortunately the movie Doraemon: Nobita's Great Battle of the Mermaid King is not yet available on HBO Max.
| Sound | Kan Sawada | Music |
| Directing | Kozo Kusuba | Director |
| Visual Effects | Tomohiro Nishiyama | Compositing Artist |
| Visual Effects | Shingo Okano | Key Animation |
| Visual Effects | Maziro | Key Animation |
| Visual Effects | Hiroshi Shimizu | Key Animation |
| Visual Effects | Takayuki Gotan | Key Animation |
| Visual Effects | Takeshi Yamazaki | Key Animation |
| Visual Effects | Akiko Matsuo | Key Animation |
| Visual Effects | Yu Yamashita | Key Animation |
| Visual Effects | Osamu Ohkubo | Key Animation |
| Production | Takanori Okano | Production Assistant |
| Visual Effects | Masahiro Kumagai | Compositing Artist |
| Writing | Yuichi Shinbo | Screenplay |
| Production | Mariko Kawanishi | Production Assistant |
| Writing | Fujiko F. Fujio | Comic Book |
| Visual Effects | Futoshi Suzuki | Key Animation |
