Forbidden Worlds #3 is a pre-Code horror and fantasy anthology from the American Comics Group (ACG), cover-dated November 1951. The issue collects seven self-contained tales of the supernatural: Lair of the Vampire, The Return, The Vengeful Spirit, The Domain of the Doomed, Giants on the Earth, Skull of the Sorcerer, and Pursuit Into the Past. Readers follow Gloria as she is trapped in a vampire's mountaintop lair, a couple flung into space onto a purgatory planet of atomic mutants, and the boy Davey Knox, who summons a vengeful sorcerer's spirit from a skull on his father's desk.

The issue's centerpiece, Skull of the Sorcerer, is one of the most celebrated stories of the Golden Age: pencilled by EC legend Al Williamson, inked by Joe Orlando and Wally Wood, with one panel inked by Frank Frazetta himself. ACG, guided by editor Richard E. Hughes, had pioneered the ongoing horror title with Adventures into the Unknown in 1948, and Forbidden Worlds became its companion series — anthology horror with an unusually literate, atmospheric tone for its era.

Today the issue is prized both as a collectible and as a historical artifact. It captures the brief, creatively explosive window of pre-Code horror before the 1954 Senate hearings reshaped the industry, and it showcases future giants — Williamson, Frazetta, Wood, Orlando — at the very start of their careers. Because ACG's pre-1964 copyrights were never renewed, the issue is now public domain in the United States, making it freely readable and a frequent subject of reprint anthologies and scholarship.