Dayton is a borough in Armstrong County, Pennsylvania, United States.

[3] The Thomas Marshall House was listed on the National Register of Historic Places in 1976, and is home to the Dayton Area Local History Society.

According to the United States Census Bureau, the borough has a total area of 0.39 square miles (1.0 km2), all land.

There were 254 housing units at an average density of 565.1 per square mile (218.2/km2).

31.9% of all households were made up of individuals, and 17.0% had someone living alone who was 65 years of age or older.