The Black Widow (1947) is a Republic Movie serial. Thirteen episodes were made.

The Editor of the Daily Clarion newspaper hires amateur criminologist Steve Colt to solve a series of murders, all involving poisonous spider bites.

Meanwhile, King Hitomu has sent his daughter Sombra to the United States to fulfill his plan for global domination. There she poses as a fortune teller and, with a gang of henchmen, attempts to steal a prototype Atomic Rocket Engine.