Sandro Castelli was born in 1973 in São Paulo, Brazil, where he lives and works as a freelance illustrator. He graduated from an art school focused on comics and illustration, and complemented his studies with several free courses in the areas of perspective, calligraphy, life drawing, etc.

He contributed regularly to some of the most important Brazilian publications: Folha de S. Paulo newspaper, publishers Abril (Veja, Playboy, Superinteressante magazines), Globo (Época, Galileu, Criativa magazines), Martins Fontes, Ática, Saraiva, FTD, etc. Institutional clients include FGV (Getúlio Vargas Foundation), FAPESP (São Paulo State Research Support Foundation), and MinCT (Ministry of Science and Technology), as well as several NGOs. His international production includes covers and images for magazines such as Apex Digest and Shimmer Magazine and publishers such as Kensington Books and Subterranean Press.

He was the winner of the 3rd Concurso Folha de Ilustração e Humor competition, in the Scientific Illustration category (2006).

He exhibited works at FIQ (International Comic Festival, BH, 2003) and at Mostra Front (SP, 2003), at the Ilustrando em Revista - FAAP (SP, 2005) exhibition and at the group show Vontade de Saber (SP, 2008), among others.