Population Demographics
As of 2025 the population of Union County is 42,378. The population is expected to shrink to 42,124 by 2030 - a growth rate of -0.12%.
The median age of Union County residents is 40.
The diversity index of Union County is 31.7, meaning that there is a 32% chance that any two people selected out of 100 residents will be of different race or ethnicity from one another.

