Kinsman is an unincorporated community and census-designated place in southern Kinsman Township, Trumbull County, Ohio, United States. Its population was 616 as of the 2010 census. Although it is unincorporated, it has a post office, with the ZIP code of 44428; as well as a library, the Kinsman Free Public Library. It lies along State Route 7 between Andover and Hubbard.Kinsman is named for John Kinsman, a land agent.The community is part of the Youngstown–Warren–Boardman, OH-PA Metropolitan Statistical Area.