Marvelous Melmo (ふしぎなメルモ, Fushigi na Merumo) is a magical girl manga and anime by Osamu Tezuka.

This series centered on Melmo, a nine-year-old girl whose mother is killed in an auto accident and has to then take care of her two younger brothers (Totoo and Touch).

This was only the case of the anime; the manga had Melmo's clothes change with her into whatever she desired (ranging from a police uniform to a fairy costume).

Although most of the episodes of the anime revolve around adventure stories, Tezuka intended the series to also function as a kind of introductory sex education for children and Darwinist evolution.

When the manga first appeared in 1970, it was originally titled Mamaa-chan, but by the time the anime debuted in 1971, the name of the main character was changed to "Melmo" (derived from "metamorphose") due to "Mamaa" having been previously trademarked.

The series re-aired in 1998 on the Japanese satellite channel WOWOW as Marvelous Melmo Renewal (ふしぎなメルモ リニューアル, Fushigi na Merumo Rinyūaru).