National Register of Historic Places listings in Allen County, Ohio

This is a list of the National Register of Historic Places listings in Allen County, Ohio.

This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Allen County, Ohio, United States. The locations of National Register properties and districts for which the latitude and longitude coordinates are included below, may be seen in an online map.

There are 31 properties and districts listed on the National Register in the county, including 1 National Historic Landmark. Another 2 properties were once listed but have been removed.

Current listings

 * }

Former listings

 * }