Union County is the name of seventeen counties in the United States: *

Union County, Arkansas Union County is a county located on the central southern border of the U.S. state of Arkansas. As of the 2010 census, the population was 41,639. The county seat is El Dorado. The county was formed on November 2, 1829, and named in recognition ...

* Union County, Florida * Union County, Georgia *

Union County, Illinois Union County is a county located in the U.S. state of Illinois. According to the 2020 United States Census, it had a population of 17,244. Its county seat is Jonesboro. It is located in the southern portion of Illinois known locally as " Little ...

* Union County, Indiana *

Union County, Iowa Union County is a county located in the southern part of the U.S. state of Iowa. As of the 2020 census, the population was 12,138. The county seat is Creston. Organized at a time of tensions before the Civil War, the county was named in 1853 ...

* Union County, Kentucky * Union County, Mississippi *

Union County, New Jersey Union County is a county in the northern part of the U.S. state of New Jersey. As of the 2020 U.S. census, the county's population was 575,345, making it the seventh-most populous of New Jersey's 21 counties. Its county seat is Elizabeth.

, the most populous Union County in the country *

Union County, New Mexico Union County ( es, Condado de la Unión, link=) is the northeasternmost county in the U.S. state of New Mexico. As of the 2010 census, the population was 4,549, making it the fourth-least populous county in New Mexico. Its county seat is Clayt ...

Union County, North Carolina Union County is a county located in the U.S. state of North Carolina. As of the 2020 census, the population was 238,267. Its county seat is Monroe. Union County is included in the Charlotte-Concord- Gastonia, NC- SC Metropolitan Statistical Ar ...

* Union County, Ohio * Union County, Oregon *

Union County, Pennsylvania Union County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 42,681. Its county seat is Lewisburg. The county was created on March 22, 1813, from part of Northumberland County. Its name is an allusio ...

Union County, South Carolina Union County is a county located in the U.S. state of South Carolina. As of the 2020 census, the population was 27,244. Its county seat is Union. The county was created in 1785. Union County is coterminous with the Union, SC, Micropolitan Sta ...

* Union County, South Dakota * Union County, Tennessee

See also