The Omaha are a Native American nation that currently resides on the Omaha Reservation in northeastern Nebraska and western Iowa, United States.

The Omaha Indian Reservation lies primarily in the southern part of Thurston County and northeastern Cuming County, Nebraska, but small parts extend into the northeast corner of Burt County and across the Missouri River into Monona County, Iowa.

Its total land area is 796.355 km² (307.474 sq mi) and a population of 5,194 was recorded in the 2000 census.

While living at "The Big Village" (Ton-wa-tonga) in current-day Dakota County in northeast Nebraska, the Omaha develop an extensive trade network with early white explorers and voyageurs.

Never known to take up arms against the U.S., members of the tribe assist  the U.S. during the American Civil War.

Omaha, Nebraska, the largest city in Nebraska, is named after them.

The Omaha speak a Siouan language which is very similar to that spoken by the Ponca, who were once a part of the Omaha before splitting off into a separate tribe in the mid-eighteenth century.