Dayton is a home rule-class city along a bend of the Ohio River in Campbell County, Kentucky, in the United States. The population was 5,338 at the 2010 census. It is less than 3 miles (5 km) from downtown Cincinnati, Ohio.
Dayton is located in the northernmost part of Campbell County at 39°6′42″N 84°28′13″W (39.111781, −84.470401), on the inside of a bend in the Ohio River. It is the most northernmost community in Kentucky as well. Dayton is bordered by Bellevue to the southwest and Fort Thomas to the southeast. To the north, across the Ohio River, is Cincinnati in Hamilton County, Ohio. The closest bridge across the Ohio is the Daniel Carter Beard Bridge on Interstate 471, connecting Newport with Cincinnati.
According to the United States Census Bureau, Dayton has a total area of 1.9 square miles (5.0 km2), of which 1.3 square miles (3.3 km2) is land and 0.66 square miles (1.7 km2), or 33.61%, is water. Dayton is located within Kentucky's Outer Bluegrass region in the Upper South.