Esteban: Child of the Sun (Japanese: 太陽の子エステバン, Hepburn: Taiyō no Ko Esuteban), known outside of Japan as the first season of The Mysterious Cities of Gold (French: Les Mystérieuses Cités d'Or), is a French-Japanese animated series which was produced by MK, NHK, DiC Audiovisuel, CLT and animated by Studio Pierrot.

The series was originally broadcast in Japan and the French version, edited with different characterization and music, was subsequently redubbed and distributed in many countries. It is currently licensed for English-language home video release in the United Kingdom, Australia, and North America by Fabulous Films.

When it was rebroadcast in Japan on NHK BS2 from 1998 to 1999, the animation was imported back from France and the audio was redubbed. NHK had erased the original VTR when their contract expired, and the rights holder had lost the master copy. The voice actress for the main character, Esteban, was the only one to reprise her role.

A sequel, serving as a three season continuation of the original, premiered in 2012.