National Register of Historic Places listings in Washington County, Iowa

This is a list of the National Register of Historic Places listings in Washington County, Iowa.

This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Washington County, Iowa, 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 18 properties and districts listed on the National Register in the county. Another 3 properties were once listed but have been removed.