Cayuga County is a county in the U.S. state of New York. As of the 2020 census, the population was 76,248. Its county seat and largest city is Auburn. The county was named for the Cayuga people, one of the Native American tribes in the Iroquois Confederation. Cayuga County comprises the Auburn, NY Micropolitan Statistical Area, which is also included in the Syracuse-Auburn, NY Combined Statistical Area.