Omaha is the most populous city in the U.S. state of Nebraska. It is located in the Midwestern United States along the Missouri River, about 10 mi (15 km) north of the mouth of the Platte River. Omaha had a population of 486,051 at the 2020 census, making it the 41st-most populous U.S. city. The eight-county Omaha–Council Bluffs metropolitan area extending into Iowa has approximately 1 million residents, the 55th-largest metropolitan area in the U.S. It is the county seat of Douglas County.