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.

Penn Yan is an incorporated village and the county seat of Yates County, New York, United States. The population was 5,159 at the 2010 census. It lies at the north end of the east branch of Keuka Lake, one of the Finger Lakes. Penn Yan, New York is home to one of the oldest mills in the United States, The Birkett Mills, founded in 1797.