Yates County is a county in the U.S. state of New York. As of the 2020 Census, the population was 24,774, making it the third-least populous county in New York. The county seat is Penn Yan. The name is in honor of Joseph C. Yates, who as Governor of New York signed the act establishing the county. The county is part of the Finger Lakes region of the state. Yates County is included in the Rochester, NY Metropolitan Statistical Area.