Iowa - Role: Building
| Gallup, George H., House |
| Gamble, James, House |
| Gannon, M. V., House |
| Garland House |
| G.A.R. Memorial Hall |
| Garner, J.W., Building |
| Garretson, Owen A. and Emma J., House |
| Gaspard, D. Julius, House |
| Gehlen House and Barn |
| German Bank |
| German Bank Building of Walnut, Iowa |
| German Evangelical Reformed Church |
| Germania-Miller/Standard Hotel |
| German Methodist Episcopal Church |
| Gibbs, E. H., House |
| Gibson, E. R., House |
| Gillette, Guy M. and Rose (Freeman), House |
| Gingrich, Clement B., House |
| Glaspell, Isaac, House |
| Glick-Sower House |
| Gobble and Heer-Spurgeons Building |
| Godard, Milton, House |
| Goering, Jacob, House |
| Goldenrod Schoolhouse |
| Goode, Lowry W., and Hattie N., First North Des Moines House |
| Goodnow Hall |
| Goodrich, William T., House |
| Gracehill Moravian Church and Cemetery |
| Graceland Cemetery Chapel |
| Grace Methodist Episcopal Church |
| Grand Auditorium and Hotel Block |
| Grand Opera House |
| Grand View College (Old Main) |
| Granger House |
| Grant, Douglas and Charlotte, House |
| Grant Vocational High School |
| Greek Orthodox Church of Saint George |
| Greene County Courthouse |
| Green, William, House |
| Greenwood Cemetery Chapel |
| Grilk, Charles, House |
| Grimes Octagon Barn |
| Grinnell Herald Building |
| Grinnell, Levi P., House |
| Griswold National Bank |
| Grocers Wholesale Company Building |
| Grundy Center High School |
| Grundy County Courthouse |
| Gruwell and Crew General Store |
| Guiberson House |
| Guttenberg Corn Canning Co. |
| Guttenberg State Bank |
| Guy, Finley, Building |
| Haberkorn House and Farmstead |
| Hager, Otto J., House |
| Haley, F.E., Double House |
| Hallett Flat-Rawson & Co. Apartment Building |
| Hall, Hannah Morse Fowler, House |
| Hall, Israel, House |
| Hall, James Norman, House |
| Hamburg Public Library |
| Hamilton Brothers Building |
| Ham, Mathias, House |
| Hancock, Charles T., House |
| Hancock County Courthouse |
| Haner, William, Polygonal Barn |
| Hansen, Andrew P., Farmstead |
| Hanson, Alfred, House |
| Harbach, L. and Sons Furniture Warehouse and Factory Complex |
| Hardacre Theater |
| Hardin County Courthouse |
| Hardware Building |
| Harker House |
| Harlan House Hotel |
| Harlan-Lincoln House |
| Harper and McIntire Company Warehouse |
| Harriman, Dr. O. B., House |
| Harris, Dr. Percy and Lileah, House |
| Harrison County Courthouse |
| Harrison, E. H., House |
| Harris Wagon and Carriage Shop |
| Hart, Charles Walter, House |
| Harvat, Emma J., and Mary E. Stach House |
| Hatton, Dr. John B. and Anna M., House |
| Hauschild's Hall |
| Hawarden City Hall, Fire Station and Auditorium |
| Hawkeye Insurance Company Building |
| Hawkeye Transfer Company Warehouse |
| Hawthorne Glove and Novelty Company-Shrader Drug Company Building |
| Hayesville Independent School |
| Hayes, William B., House |
| Hays, E. R., House |
| Hebard, Alfred, House |
| Hebert, Louis, House |
| Hedge Block |
| Heinz, Bonaventura, House (second) |
| Henderson, Daniel and Nancy Swaford, House |
| Henne, Robert, House |
| Henn Mansion |
| Henry County Courthouse |
Data from United States Park Service and Wikidata
