Parkman is a census-designated place in southern Parkman Township, Geauga County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 44080. It lies along U.S. Route 422 at its intersection with State Routes 88, 168, and 528.Parkman was laid out in 1804. The community has the name of Samuel Parkman, an official with the Connecticut Land Company. A post office called Parkman has been in operation since 1806.Seth Ledyard Phelps, United States Navy officer, politician, and diplomat was born in Parkman.