The Unknown Terror
- taona: 1957
- Firenena: United States of America
- Genre: Horror
- Studio: Emirau Productions, Regal Films
- Keyword: amazon rainforest, mad scientist, missing person, underground cavern, man with limp, fungus people, primitive village
- tale: Charles Marquis Warren
- Cast: John Howard, Mala Powers, Paul Richards, May Wynn, Gerald Milton, Duane Grey