Union City is a city in and the county seat of Obion County, Tennessee, United States. 11,170 people were living in the town as of the 2020 census. It is the principal urban settlement of the surrounding micropolitan area, which includes Obion County and Fulton County, Kentucky. Union City is home to Discovery Park of America which is a museum with many exhibits pertaining to local history, as well as state, national, and world history, science, technology, and art.