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 is a county located in the north central portion of the U.S. state of Florida, the smallest in the state. As of the 2020 census, the population was 16,147. The county seat is Lake Butler. With a personal per capita income of $20, ...

Union County, Georgia Union County is a county located in the north central portion of the U.S. state of Georgia. As of the 2020 census, the population was 24,632. The county seat is Blairsville. History Union County was originally a core part of the homeland of ...

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 is a county in the U.S. state of Indiana. As of the 2020 United States census, the population was 7,087. The county seat is Liberty. Since 2018, Union County has been included in the Cincinnati-Middletown, OH-KY-IN Metropolitan St ...

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 is a county in the U.S. state of Kentucky. As of the 2020 United States census, the population was 13,668. Its county seat is Morganfield. The county was created effective January 15, 1811. The county is located on the left (east) ...

Union County, Mississippi Union County is a county located in the U.S. state of Mississippi. As of the 2010 census, the population was 27,134. Its county seat is New Albany. According to most sources, the county received its name by being a union of pieces of several ...

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 is a county located in the U.S. state of Ohio. As of the 2020 census, the population was 62,784. Its county seat is Marysville. Its name is reflective of its origins, it being the union of portions of Franklin, Delaware, Madis ...

Union County, Oregon Union County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 26,196. Its county seat is La Grande. Union County comprises the La Grande, OR Micropolitan Statistical Area. It is one of the eig ...

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 is the southernmost county in the U.S. state of South Dakota. As of the 2020 United States Census, the population was 16,811, making it the 13th most populous county in South Dakota. Its county seat has been Elk Point since April ...

Union County, Tennessee Union County is a county located in the U.S. state of Tennessee. As of the 2010 census, its population was 19,109. Its county seat is Maynardville. Union County is included in the Knoxville metropolitan statistical area. History Union County ...

See also