Union is a city in Montgomery and Miami Counties in the U.S. state of Ohio.

Ironically, Union lies west of West Union, Ohio, the county seat of Adams County approximately 60 miles east of Cincinnati.

The current mayor is Michael O'Callaghan,[7] and John P. Applegate is Union's city manager.

24.3% of all households were made up of individuals, and 9.2% had someone living alone who was 65 years of age or older.

18.9% of all households were made up of individuals, and 5.6% had someone living alone who was 65 years of age or older.

Union residents in Montgomery County west of the Stillwater River are served by the Northmont City School District.

[14] The schools that Union children attend include: East of the Stillwater River, in Montgomery County,[14] students attend Vandalia-Butler City School District.

[15] Portions in Miami County in Milton-Union Exempted Village School District.