Smithfield was a village in Smithfield Township, Jefferson County, Ohio, United States. The population was 869 at the 2010 census. It is part of the Weirton–Steubenville, WV-OH Metropolitan Statistical Area. In 2019, Smithfield voted to dissolve itself.

Smithfield Township is one of the fourteen townships of Jefferson County, Ohio, United States. The 2020 census found 3,011 people in the township.