Union County may refer to:
Counties in the United States Union County, Arkansas Union County, Florida Union County, Georgia Union County, Illinois Union County, Indiana Union County, Iowa Union County, Kentucky Union County, Mississippi Union County, New Jersey, the most populous Union County in the country Union County, New Mexico Union County, North Carolina Union County, Ohio Union County, Oregon Union County, Pennsylvania Union County, South Carolina Union County, South Dakota Union County, Tennessee
Film Union County (film), a 2026 drama film
See also Union Parish, Louisiana