Ohio - Role: Building
| Courtland, The |
| Court Street Firehouse |
| Covenant First Presbyterian Church |
| Covington Historic Government Building |
| Cox, George B., House |
| Cox, Jacob D., House |
| Cozad, Justus L., House |
| Crabill, David, House |
| Craft Master Building |
| Crafts William H., House |
| Crane, Jonathan, Farm |
| Crawfis Institute |
| Crawford-Tilden Apartments |
| Crescent Hill |
| Crescent, The |
| Crestline City Hall |
| Crist Tavern Annex-Millworkers Boarding House |
| Croco House |
| Cronenwett, Georg, House |
| Crosley Building |
| Crossed Keys Tavern |
| Crumrine, John, Farm |
| Crumrine, Michael, Farm |
| Crystal Lake Stock Farm |
| Culbertson, Robert, House |
| Culbertson, William, House |
| Cummings, Wilson S., House |
| Cummins, David, Octagon House |
| Cummins School |
| Cunningham-Maier House |
| Curtiss, Marcus, Inn |
| Curtis, Walter, House |
| Curtis, William D., House |
| Cuvier Press Club |
| Dairy Barn–Boys’ Industrial School |
| Dall, Andrew, Jr. and James, Houses |
| Damascus Grade School |
| Damon, George, House |
| Danalds, Samuel, House |
| Dana, Marcus, House |
| Danford, Samuel, Farm, Church and Cemetery |
| Darke County Courthouse, Sheriff's House, And Jail |
| Darrow, Clarence, Octagon House |
| Datz, Walter, House |
| Davey, John, House |
| David's Reformed Church |
| Davis, Alexander, Cabin |
| Davis, Alexander, House |
| Davis and Dague Grocery Store, Old |
| Davis, Anson, House |
| Davis, Anson, Springhouse |
| Davis, James, Barn |
| Davis, James, Farm |
| Davis Mill |
| Davis, Samuel Henry, House |
| Davis, Samuel, House |
| Day, Erastus, House |
| Dayton Arcade |
| Dayton Art Institute |
| Dayton Canoe Club |
| Dayton Daily News Building |
| Dayton Fire Department Station No. 16 |
| Dayton Fire Station No. 14 |
| Dayton, James, House |
| Dayton, James, House, II |
| Dayton Stove and Cornice Works |
| Dayton Women's Club |
| Dayton Young Men's Christian Association Building |
| Dean Family Farm |
| Deardoff, Daniel L., House |
| Decker, Elias, Farmhouse |
| Decker, Henry, Farmstead |
| Decker, Stephen, Rowhouse |
| Deeds' Barn |
| Deerlick Farm |
| Deerwood Farm |
| Defiance High School |
| Defiance Public Library |
| DeHeck, Albert, House |
| Deis, John, House |
| Deitz, Samuel, Farmhouse |
| Delashment, Elias, House |
| Delaware County Courthouse |
| Delaware County Jail and Sheriff's Residence |
| Delaware Post Office |
| Delaware Public Library |
| Delco Building |
| Del Monte Apartments |
| Demand-Gest House |
| Deming, Col. Simeon, House |
| Denison, William, House |
| Dennison High School |
| Denzel, John, House |
| Derby, H. W., Building |
| Detmer, A. M., House |
| Detrick Milling and Distilling Company |
| Detroit-Warren Building |
| Detwiller, John, Tavern and Farmstead |
| Deuscher, Henry P., House |
| DeVilbiss Manufacturing Building |
Data from United States Park Service and Wikidata
