Born in Madrid, James A. Castillo began his career in animation more than a decade ago. He is an Emmy winning director and creator based between Madrid and Los Angeles. 

As a designer he has contributed to the art departments of some of the most prominent animation studios in Europe and the United States. Throughout his career, he has worked as an art director, concept designer, character designer, and storyboard artist for major studios including Sony Pictures, Disney, Paramount Pictures, Netflix, and Warner Bros.. His credits include acclaimed animated productions such as Teenage Mutant Ninja Turtles: Mutant Mayhem and The Mitchells vs. the Machines, among others. Known for his visually striking style and strong storytelling sensibility, Castillo has built a reputation for blending cinematic atmosphere with bold character-driven design. In 2024, he was awarded at the Concept Art Awards for outstanding character design for a TV production. 

Castillo made his directorial debut with the virtual reality film Madrid Noir, released by Meta Quest (formerly Oculus) in the summer of 2021. The project premiered to critical acclaim, screened at more than a dozen international festivals, and received several awards. In 2022, Madrid Noir won the prestigious Primetime Emmy Awards for Outstanding Interactive Media, establishing Castillo as one of the emerging voices in innovative animated storytelling. The project was especially praised for its unique blend of noir aesthetics, immersive VR technology, and emotional narrative design.

His second directorial work, The Quinta's Ghost, premiered in 2025 at the Tribeca Festival in New York City. Since then, the short film has screened at more than 50 festivals worldwide and has won nearly 30 awards, including two prestigious Méliès d’Argent awards at Sitges Film Festival and Ramsvik Horror Film Festival, as well as honors from Premios Quirino, ALCINE, BIFAN, the Guadalajara International Film Festival, Skyline, and the San Sebastián Horror and Fantasy Film Week, among others. The film is currently nominated for the Premios Fugaz, qualified for the Goya Awards, and was also shortlisted for consideration by the Academy of Motion Picture Arts and Sciences.

In 2023, Castillo founded Martirio Films, an independent animation studio focused on fostering adult-oriented animation in Spain while maintaining a strong international outlook. Through the company, he aims to champion original storytelling, auteur-driven projects, and innovative approaches to animated cinema. His work often explores themes of memory, identity, mystery, and urban folklore, combining stylized visuals with emotionally grounded narratives.