Union City is a village in Darke County, Ohio, United States.

Incorporation came during a period of growth occasioned by the opening of a line of the Greenville and Miami Railroad through the town on December 12, 1852.

There were 754 housing units at an average density of 819.6 per square mile (316.4/km2).

31.4% of all households were made up of individuals, and 12.5% had someone living alone who was 65 years of age or older.

There were 780 housing units at an average density of 847.1 per square mile (327.1/km2).

29.0% of all households were made up of individuals, and 14.5% had someone living alone who was 65 years of age or older.