Dillonvale is a village in southern Jefferson County, Ohio, United States. The population was 589 at the 2020 census. It is part of the Weirton–Steubenville metropolitan area. Charles Eberle was the first mayor of Dillonvale and was the first Postmaster as well.

Jefferson County is a county located in the U.S. state of Ohio. As of the 2020 census, the population was 65,249. Its county seat is Steubenville. The county is named for Thomas Jefferson, who was vice president at the time of its creation.