Cozad is a city in Dawson County, Nebraska, United States. The population was 3,977 at the 2010 census. The town is on the Great Plains of central Nebraska, along the Union Pacific Railroad and U.S. Highway 30, just north of the Platte River. The 100th meridian, which roughly marks the eastward boundary of the arid plains, passes just west of the town as is marked nearby on a prominent sign across U.S.