Otsego County, formerly known as Okkuddo County, is a county located in the U.S. state of Michigan. As of the 2020 census, the population was 25,091. The county seat is Gaylord. The county was founded in 1840 and organized in 1875.

Otsego County is a county in the U.S. state of New York located within the Mohawk Valley Region. As of the 2020 census, the population was 58,524. The county seat is Cooperstown. The county's population center is Oneonta. The name Otsego is from a Mohawk or Oneida word meaning "place of the rock." The county is part of the Mohawk Valley region of the state.