TMDb/Supergirl Celebrity Celebrate Superman Day with DC's new Krypto short & Supergirl's 2026 spotlight. Explore the legacy of the Man of Steel and his iconic family. April 19, 2026 AceShowbiz - Nearly nine decades ago, the world met Superman in Action Comics #1, a milestone that forever transformed comic books and superhero movies. This iconic event is commemorated annually as Superman Day by DC, celebrating the legacy of the Man of Steel.