Ohio - Significance region: Local
| Galbreath, John, Mound |
| Galigher, James, House |
| Gallagher Building |
| Gallipolis Historic District |
| Gallipolis Public Square and Garden Lots Historic District |
| Gambier Historic District |
| Gantz Homestead |
| Gardner House |
| Garfield, Halsey, House |
| Garfield, James A., House |
| Garfield Library |
| Garfield Terrace Apartments |
| Garford, Arthur L., House |
| Garlick, Richard, House |
| Garst House |
| Garst, John, House |
| Garver Brothers Store |
| Gasche, Charles, House |
| Gaskins-Malany House |
| Gast, Matthias, House and General Store |
| Gaston's Mill-Lock No. 36, Sandy And Beaver Canal District |
| Gatch Site |
| Gates, Holsey, House |
| Gates Mills Historic District |
| Gates Mills Village Historic District |
| Gatewood |
| Gayer, Jacob, House |
| Gayer, Jacob M., House |
| Gayman, Christian, House |
| Gelpi, Eleanor A., House |
| Gendron, Peter, House |
| General Hospital Nurses' Home |
| General U.S. Grant Bridge |
| Genoa Town Hall |
| George-Caldwell-Grum Farm |
| Georgetown Public School |
| German Evangelical Protestant Cemetery Chapel |
| German Village Historic District |
| Gerrard, Stephen A., Mansion |
| Gertenslager Carriage and Wagon Company |
| Gharky, George H., House |
| Ghent Historic District |
| Gibson House |
| Gifford, Dr. William, House |
| Gilbert, F.A., House |
| Gilbert House |
| Gilbert, Jane, House |
| Gilbert, Philip E., Houses |
| Gilbert Row |
| Gilbert-Sinton Historic District |
| Gilbert-Wilcox House |
| Gilboa Main Street Historic District |
| Gilchrist, Capt., House |
| Gilchrist, Capt., Sr., House |
| Gilcrist House |
| Gillett-Shoemaker-Welsh House |
| Gill, H., House |
| Gill, John, Farmstead |
| Gill-Luchsinger-Bahnsen House and Barn |
| Gill-Morris Farm |
| Gish Farmhouses |
| Gist Settlement Historic District |
| Glamorgan |
| Gleason, Edmund, House |
| Glencoe-Auburn Hotel and Clecoe-Auburn Place Row Houses |
| Glendale Cemetery |
| Glendale Police Station |
| Glendale Steps |
| Glen Echo Historic District |
| Glenford Bank |
| Glenford Fort |
| Glidden, Francis K., House |
| Globe Iron Works Building |
| Godfrey-Johnson House |
| Godman, H.C., Co. Building |
| Godwin-Knowles House |
| Golden Eagle Wine Cellars |
| Golden Lamb |
| Goldsmith, Moses, Building |
| Goll Homestead |
| Goodall Building |
| Gooding House and Tavern |
| Goodwin, Dr. Erastus, House |
| Goodyear Hall-Ohio Savings and Trust Company |
| Gordon Square Building |
| Gordon Square Historic District |
| Gorsuch, Ernest J., House |
| Goshorn, Sir Alfred T., House |
| Gothic Building, The |
| Gothic Revival House |
| Gottschall, Oscar M., House |
| Gould Block |
| Governor's Inn |
| Grace Church |
| Grace Episcopal Church |
| Grace Reformed Church |
| Graefe, Henry, House |
| Grafton-Rockwood Historic District |
| Grafton School |
| Graham, William, House |
Data from United States Park Service and Wikidata
