Ohio - Criteria: C (architecture/engineering)
| Griffin, Alexander B., House |
| Griffith, James, House |
| Griswold Memorial Young Women's Christian Association |
| Griswold, Peck, House |
| Groesbeck, Grace, House |
| Gross, L.N., Company Building |
| Groveport Log Houses |
| Groveport School |
| Groveport Town Hall Historic Group |
| Groveport United Methodist Church |
| Gruen Watch Company-Time Hill |
| Guernsey County Courthouse |
| Gummer House |
| Gunn House |
| Gurney-Kochheiser House |
| Gwinn Estate |
| Gwynne Building |
| Hackenberg, Harvey, House |
| Haddon Hall |
| Haffey, Parley, Farm Complex |
| Haines, Frank, House |
| Haines House |
| Hale, Jonathan, Homestead |
| Halle Building |
| Halle's Shaker Square |
| Hamer's General Store |
| Hamilton Catholic High School |
| Hamilton County Memorial Building |
| Hamilton, Gilbert H., House |
| Hamilton Historic Civic Center |
| Hamilton-Ickes House |
| Hamilton, J. L., Residence |
| Hamilton Park Historic District |
| Hamlet, The |
| Hancock and Dow Building |
| Hancock County Courthouse |
| Hangar, The |
| Hanitch-Huffman House |
| Hannaford, Samuel, House |
| Hanna House |
| Hanna, Howard M., Jr., House |
| Hanna-Kenty House |
| Hanna, Leonard C., Jr., Estate |
| Hanoverton Canal Town District |
| Hanson House |
| Hardesty, Ralph, Stone House |
| Hardin County Courthouse |
| Harding-Jones Paper Company District |
| Harding Tomb |
| Harmar Historic District |
| Harmon, Francis E., House |
| Harp Apartments |
| Harper-Cosgrave Block |
| Harper Mausoleum and Harper, George W., Memorial Entrance |
| Harper, Samuel, Stone House |
| Harpersfield Covered Bridge |
| Harper, William Rainey, Log House |
| Harra Covered Bridge |
| Harris, Franklin, Farmstead |
| Harrison County Courthouse |
| Harrison-Landers House |
| Harrison National Bank |
| Harris, Stephen R., House |
| Harris, William B., House |
| Harshaville Covered Bridge |
| Harshey, John, Residence |
| Harshman Covered Bridge |
| Hart, Gideon, House |
| Hart, Lucy, House |
| Hart's Drug Store |
| Harvard Company-Weber Dental Manufacturing Company |
| Harvard School |
| Harvey One-Room School |
| Harwood Block |
| Haskins, Liberty Whitcomb, House |
| Hatch, George, House |
| Hathaway, Lot, House |
| Hatton Farm |
| Hawthorn Hill |
| Hayden Building |
| Haydenville Historic Town |
| Hayesville Opera House |
| Hay-McKinney and Bingham-Hanna House |
| Hayner, Mary Jane, House |
| Headley Inn., Smith House And Farm |
| Heckler Farmhouse |
| Hedges-Hunter-Keller-Bacon Gristmill |
| Heeter-Russo House |
| Heights Rockfeller Building |
| Helen Chapel |
| Heller, Edward, Residence |
| Helmick Covered Bridge |
| Helmick Mill Covered Bridge |
| Helpman-Chaney House |
| Hemann, Joseph A., House |
| Hemminger Saloon |
| Henderson, Dr. David W., House |
| Henderson, John, House |
| Hendry, Francis, House |
| Henn, Albert W., Mansion |
Data from United States Park Service and Wikidata
