Juan Ferreyra started drawing comics professionally at Image Comics with the series Small Gods, and then Lazarus and Emissary. He then worked for Dark Horse Comics on Rex Mundi, Falling Skies, Kiss Me Satan, Colder, Colder: The Bad Seed, Colder: Toss the Bones, and Prometheus: Fire and Stone.
He also collaborated on Creepy, Dark Horse Presents and Abe Sapien, as well as colored comics like Conan and Solomon Kane. Juan then worked for the French market doing a series called La 6eme Heure for Soleil.
He also did the conceptual art for the Oscar-nominated movie Wild Tales from Damian Szifron.
At DC Juan has worked on covers for CONSTANTINE and THE NEW SUICIDE SQUAD, as well as interiors for CONSTANTINE, BATMAN ETERNAL, GOTHAM BY MIDNIGHT and THE NEW SUICIDE SQUAD.