This is a list of the National Register of Historic Places listings in Seneca County, Ohio.
This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Seneca 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 45 properties and districts listed on the National Register in the county. Another property was once listed but has been removed.
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