Coza is a city in Dawson County, Nebraska, United States. The population was 4,163 at the 2000 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 through the town as is marked by a prominent sign across U.S. Highway 30. In the early 1860s, it was a stop along the Pony Express.