Oneota is a designation archaeologists use to refer to a cultural complex that existed in the eastern plains and Great Lakes area of what is now the United States from around AD 900 to around 1650 or 1700. The culture is believed to have transitioned into various Macro-Siouan cultures of the protohistoric and historic times such as Ioway. A long-accepted ancestry to the Ho-chunk has yet to be conclusively demonstrated.

Oneota is considered a major component of Upper Mississippian culture. It is characterized by globular, shell-tempered pottery that is often coarse in fibre. It often had a spherical body, short necks and/or a flat lip. Sometimes the vessels had strap handles. Decoration includes wavy and zigzag lines, often in parallel. Most decoration was done on the top half of the vessel. Analytically, the culture has been broken down into various stages or horizons. Generally accepted are the following: the Emergent Horizon (ca. AD 900-1000), the Developmental Horizon (ca. AD 1000-1300), the Classic Horizon (ca. AD 1300-1650) (previously called the Oneota Aspect), and the Historic Horizon (post-contact, generally after 1650). In addition, the Oneota culture has been divided geographically based on stylistic and socio-economic differences. Some of these traditions are Orr, Langford, and Fisher-Huber.