A bayou (pronounced or ) is a small, slow-moving stream or creek, or a lake or pool (bayou lake) that lies in an abandoned channel of a stream. Bayous are usually located in relatively flat, low-lying areas, for example, in the Mississippi River delta region of the southern United States. A bayou is frequently a slackwater anabranch or minor braid of a braided channel, that is moving with less velocity than the mainstem. Many bayous are the home of crawfish, certain species of shrimp, other shellfish, and catfish.
The word was first used by the English in Louisiana and is thought to originate from the Choctaw word bayuk, which means "small stream." The first settlements of Acadians in southern Louisiana were near Bayou Lafourche and Bayou des Ecores, which led to a close association of the bayou with Cajun culture.
Bayou Country is most closely associated with Cajun and Creole cultural groups native to the Gulf Coast region generally stretching from Houston, Texas, to Mobile, Alabama, with its center in New Orleans, Louisiana.
An alternate spelling "buyou" has also been used, as in the "Pine Buyou" used in a description by Congress in 1833 of Arkansas Territory.
Bayous are often the setting of horror movies since they are commonly seen as spooky and mysterious. Some famous horror movies that are associated or take place in bayous include The Skeleton Key, Hatchet, and The Reaping.