Hyannis is a village in Grant County, Nebraska, United States. The population was 165 at the time of the 2020 census. It is the county seat of Grant County. It is centrally located in the extensive, unique, and remote region of grasslands known as the Sandhills of Nebraska at the intersection of two Nebraska State Highways: NSH 61 which runs north and south, and NSH 2, which runs east and west.