Union County area

Population and density of Union County

The Census Bureau estimates that 267,674 people lived in Union County on July 1, 2025. That ranks #278 of 3,222 county equivalents nationally and #8 of 100 in North Carolina. Since the April 1, 2020 estimates base of 238,179, the population has grown by 29,495 (+12.4%), compared with +7.2% for North Carolina as a whole.

With 632.7 square miles of land, that is 423 people per square mile (163 per km²), placing Union County #393 nationally for density and #12 in North Carolina. The median county equivalent has 47 people per square mile; the North Carolina median is 116. Put another way, there are about 1.5 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Union County

15 incorporated places lie at least partly in Union County. Together they are home to 185,816 people (69.4%); the other 81,858 (30.6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Indian Trail town, with 44,303 residents in the county. The county seat, Monroe city, has 42,644 residents. By land, Monroe city is the largest at 33.3 mi². Among places with at least 1,000 residents in 2020, Monroe city grew fastest since then (+23.1%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Union County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Union County is a central county of the Charlotte-Concord-Gastonia, NC-SC Metropolitan Statistical Area. Its 11 county equivalents have 2,938,830 residents on 5,597.4 square miles of land; Union County accounts for 11.3% of the land and 9.1% of the residents. By combined land it ranks #39 of 393 metropolitan areas, and #21 by population. It belongs to the Charlotte-Concord, NC-SC Combined Statistical Area.

ZIP codes

12 ZIP Code Tabulation Areas have land in Union County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

280792810328104281052810728108281102811228133281732817428227

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Union County

Union County shares a land border with 6 county equivalents, including 2 in South Carolina. It has more land than 5 of them. The largest neighbor is Chesterfield County (799 mi²) and the smallest is Cabarrus County (361.3 mi²). Together with its neighbors, Union County forms a block of 3,792.3 mi² of land, of which it holds 16.7%.

How big is Union County compared with U.S. states?

Union County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.6 times as much. North Carolina’s county land could hold about 77 areas the size of Union County.

Another way to picture it: the same land area would fill a square about 25.2 miles (40.5 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Union County?

Union County has more land than 1,711 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Union County at #1,616 nationally by total area, 105 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 1.1%, compared with a national county-equivalent median of 1.2%. The two percentages are within 0.1 percentage points of each other. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Union County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.