Heart of Darkness (1899) is a novella by Polish-English novelist Joseph Conrad about a narrated voyage up the Congo River into the Congo Free State in the Heart of Africa. Charles Marlow, the narrator, tells his story to friends aboard a boat anchored on the River Thames. This setting provides the frame for Marlow's story of his obsession with the successful ivory trader Kurtz. Conrad offers parallels between London ("the greatest town on earth") and Africa as places of darkness.

Central to Conrad's work is the idea that there is little difference between "civilised people" and those described as "savages." Heart of Darkness implicitly comments on imperialism and racism.

Originally issued as a three-part serial story in Blackwood's Magazine to celebrate the thousandth edition of the magazine, Heart of Darkness has been widely re-published and translated into many languages. It provided the inspiration for Francis Ford Coppola's 1979 film Apocalypse Now. In 1998, the Modern Library ranked Heart of Darkness 67th on their list of the 100 best novels in English of the twentieth century.

This edition also includes an author biography.