West Union, IL has a population of 478 and is the 19,821st largest city in the United States. The population density is 302 per sq mi which is 36% higher than the Illinois average and 233% higher than the national average. The median age in West Union is 32 which is approximately 14% lower than the Illinois average of 37. In West Union, 79% of the population over 15 years of age are married, 98% speak English and 2% speak Spanish. 64% of West Union residents were born in Illinois, 36% were born out of state, 0% were born outside of the United States and 0% were foreign born.