New Boston is a village in Scioto County, Ohio, United States, along the Ohio River. The population was 2,298 at the 2020 census. Apart from its southern boundary on the Ohio River, New Boston is entirely surrounded by the city of Portsmouth.

Scioto County is a county along the Ohio River in the south-central part of the U.S. state of Ohio. At the 2020 census, the population was 74,008. Its county seat is Portsmouth. The county was founded on March 24, 1804, from Adams County and is named for a Native American word referring to deer or deer-hunting. Scioto County comprises the Portsmouth, OH Micropolitan Statistical Area. It is at the confluence of the Scioto and Ohio rivers.