Henri René Albert Guy de Maupassant (UK: , US: ; French: [ɡi d(ə) mopasɑ̃]; 5 August 1850 – 6 July 1893) was a 19th-century French author, remembered as a master of the short story form, and as a representative of the Naturalist school, who depicted human lives and destinies and social forces in disillusioned and often pessimistic terms.

Maupassant was a protégé of Gustave Flaubert and his stories are characterized by economy of style and efficient, effortless dénouements (outcomes). Many are set during the Franco-Prussian War of the 1870s, describing the futility of war and the innocent civilians who, caught up in events beyond their control, are permanently changed by their experiences. He wrote some 300 short stories, six novels, three travel books, and one volume of verse. His first published story, "Boule de Suif" ("Ball of Suet", 1880), is often considered his masterpiece.

He was known to consume hallucinogens and may have drawn on the experience with these substances for his stories. His work has been studied by neuroscientists due to his skill for articulating and analyzing his first hand experiences with different types of hallucinatory phenomena.