Buffalo is an unincorporated community and census-designated place in eastern Valley Township, Guernsey County, Ohio, United States. As of the 2010 census it had a population of 401. Although it is unincorporated, it has a post office, with the ZIP code of 43722. It lies along State Route 313.Buffalo is the home town of NFL coach Dom Capers.Buffalo was originally called "Hartford", and under the latter name was platted in 1836. A post office called Buffalo has been in operation since 1839.