Gypsum is an unincorporated community in eastern Portage Township, Ottawa County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 43433.
The community is named for deposits of the gypsum rock near the original town site. Gypsum mining in the area by U.S. Gypsum Corp. stopped in the 1970s.
Children from Gypsum families generally attend the Port Clinton City School District.