Southington is an unincorporated community in central Southington Township, Trumbull County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 44470. It lies at the intersection of U.S. Route 422 with State Route 305.The community is part of the Youngstown–Warren–Boardman, OH-PA Metropolitan Statistical Area.A post office called Southington has been in operation since 1826. The community takes its name from Southington Township.