Yoknapatawpha County is a fictional county created by American author William Faulkner as a setting for many of his novels. It is located in northwestern Mississippi and its seat is the town of Jefferson. Yoknapatawpha County is bounded on the north by the Tallahatchie River and on the south by the Yoknapatawpha River and has an area of 2,400 mi² (6,200 km²). Most of the eastern half (as well as a small part of the southwest corner) of the county is pine hill country.

The word Yoknapatwpha is pronounced "Yok'na pa TAW pha.". It is derived from two Chickasaw words—Yocona and petopha, meaning "split land." The compound word, however, according to Faulkner, means "water flowing slow through the flatland." Yoknapatawpha was the original name for the actual Yocona River, which runs through the southern part of Lafayette County, of which Oxford is the seat. It is widely believed by scholars that Layfayette County is the basis for Yoknapatawpha County.

The area was originally Chickasaw land. White settlement started around 1800. Prior to the Civil War, the country consisted of several large plantations: Louis Grenier's in the southeast, McCaslin's in the northeast, Sutpen's in the northwest, and Compson's and Sartoris' in the immediate vicinity of Jefferson. Later the county became mostly small farms. By 1936, the population was 15,611, of which 6,298 were whites and 9,313 were black.