The Whisperer in Darkness is a 26,000-word novella by American writer H. P. Lovecraft. Written February-September 1930, it was first published in Weird Tales, August 1931. Similar to The Colour Out of Space (1927), it is a blend of horror and science fiction. Although it makes numerous references to the Cthulhu Mythos, the story is not a central part of the mythos, but reflects a shift in Lovecraft's writing at this time towards science fiction. The story also introduces the Mi-go, an extraterrestrial race of fungoid creatures.

The story is told by Albert N. Wilmarth, an instructor of literature at Miskatonic University in Arkham, Massachusetts. When local newspapers report strange things seen floating in rivers during a historic Vermont flood, Wilmarth becomes embroiled in a controversy about the reality and significance of the sightings, though he sides with the skeptics, blaming old legends about monsters living in uninhabited hills who abduct people who venture too close to their territory.