National Register of Historic Places listings in Union County, Illinois

This is a list of the National Register of Historic Places listings in Union County, Illinois.

This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Union County, Illinois, United States. Latitude and longitude coordinates are provided for many National Register properties and districts; these locations may be seen together in a map.

There are 8 properties and districts listed on the National Register in the county. Another property was once listed but has been removed.

This National Park Service list is complete through NPS recent listings posted April 4, 2025.