Ohio - Significance region: Local
| Harvey One-Room School |
| Harwood Block |
| Haskins, Liberty Whitcomb, House |
| Hatton Farm |
| Hayden Building |
| Hayesville Opera House |
| Hay-McKinney and Bingham-Hanna House |
| Hayner, Mary Jane, House |
| Heckler Farmhouse |
| Hedges-Hunter-Keller-Bacon Gristmill |
| Heeter-Russo House |
| Heights Rockfeller Building |
| Heller, Edward, Residence |
| Helmick Mill Covered Bridge |
| Helpman-Chaney House |
| Hemann, Joseph A., House |
| Hemminger Saloon |
| Henderson, Dr. David W., House |
| Hendry, Francis, House |
| Henn, Albert W., Mansion |
| Henninger, Phillip, House |
| Henny Barn |
| Henry County Courthouse |
| Henry County Sheriff's Residence and Jail |
| Henry, Robert W., House |
| Henry W. Longfellow School |
| Hercules Motors Corporation Industrial Complex |
| Herold Building |
| Herr, Christian S., House |
| Herrington, John, House and Herrington Bethel Church |
| Herrold, Thomas Jefferson, House and Store |
| Hershey, J., Residence |
| Hertzler, Daniel, House |
| Hess, Elmer, House |
| Heter Farm |
| Hewson-Gutting House |
| Hidley, James P., Cottage |
| Higby House |
| Higgins, H. A., Building |
| Higginsport School |
| High and Gay Streets Historic District |
| Highbank Farm |
| Highbanks Metropolitan Park Mounds I and II |
| High House |
| Highland County Courthouse |
| Highland Egg and Poultry Company Building |
| High Street Commercial Block |
| Hillcrest Hotel |
| Hilliard Apartment Building |
| Hilliard Methodist Episcopal Church |
| Hill, James Delos, House |
| Hill, James, House |
| Hill, Jediah, Covered Bridge |
| Hill-Kinder Mound |
| Hillsboro Historic Business District |
| Hillside Haven Mound |
| Hinde & Dauch Paper Co. |
| Hinde & Dauch Paper Co. |
| Hinde & Dauch Paper Co. |
| Hinde, James J., House |
| Hine, Horace L., House |
| Hirons-Brown House |
| Hise, Daniel Howell, House |
| Historic Associate Reformed Church and Cemetery |
| Historic Northwest District |
| Hoadley, George, Jr., House |
| Hodgen's Cemetery Mound |
| Hoffman House |
| Hoffner Historic District |
| Holgate Avenue Historic District |
| Hollencamp House |
| Hollister-Parry House |
| Holmes County Courthouse And Jail |
| Holy Angels Church |
| Holy Cross Church, Rectory and School |
| Holy Cross Lithuanian Roman Catholic Church |
| Holy Cross Monastery and Chapel |
| Holy Rosary Church |
| Holy Rosary Roman Catholic Church Complex |
| Home Building Association Bank |
| Home for the Aged Deaf |
| Homestead Theatre Block |
| Honam, John, House |
| Hoodin Building |
| Hood-Simmons House |
| Hope Furnace |
| Hopkins, Benjamin F., Stone Building |
| Hopkins, Roswell, Residence |
| Horn Mound |
| Horsey-Barthelmas Farm |
| Horton, Capt. Charles, House |
| Hosack House |
| Hosford House |
| Hostetter Inn |
| Hotel Argonne |
| Hotel Ashtabula |
| Hotel Central |
| Hotel Harding |
| Hotel Manchester |
| Hotel Metropole |
Data from United States Park Service and Wikidata
