The name was changed to Otsego in 1843 after the county in New York, with the name ultimately deriving from a Mohawk or Oneida word meaning "place of the rock.

[1] On May 20, 2022, an EF3 tornado struck the county seat of Gaylord killing 2 and injuring 44 while causing major damage to the downtown business district and severely damaging a mobile home park.

Otsego Lake is the county's largest and has a surface area of 1,972 acres (7.98 km2).

Many of these are so-called 'kettle lakes,' formed by the melting of blocks of glacial ice, left as the glacier retreated, which created a depression in the soil.

A large portion of the area is the Grayling outwash plain, a broad outwash plain including sandy ice-disintegration ridges; jack pine barrens, some white pine-red pine forest, and northern hardwood forest.

[10] Headwaters of the Au Sable, Black, Manistee, Pigeon, and Sturgeon Rivers are in Otsego County.

[8] As of the 2000 United States census,[16] there were 23,301 people, 8,995 households, and 6,539 families residing in the county.

The county government operates the jail, maintains rural roads, operates the major local courts, records deeds, mortgages, and vital records, administers public health regulations, and participates with the state in the provision of social services.

The county board of commissioners controls the budget and has limited authority to make laws or ordinances.

In Michigan, most local government functions — police and fire, building and zoning, tax assessment, street maintenance, etc.

(information as of September 2005) The Gaylord Herald Times is the newspaper of record for Otsego County.