Iowa - Significance region: Local
| Cundill Block |
| Currier House |
| Curtis, George M., House |
| Cutler-Donahue Covered Bridge |
| Czecho Slovakian Association Hall |
| Dahlonega School #1 |
| Dallas County Courthouse |
| Damour, William and Sue, House |
| Danish Lutheran Church |
| Dau, William C. and Hertha, House |
| Davenport Bag and Paper Company Building |
| Davenport City Hall |
| Davenport Downtown Commercial Historic District |
| Davenport Hose Station No. 3 |
| Davenport Hotel |
| Davenport Motor Row and Industrial Historic District |
| Davenport Village |
| Davenport Water Co. Pumping Station No. 2 |
| Davidson Bros. Company Warehouse and Manufacturing Building |
| Davidson Building |
| Davis County Courthouse |
| Davison, Abner, House |
| Davis, Timothy, House |
| Dawley House |
| Dayton Stagecoach Inn and Tavern Historic District |
| Decatur County Courthouse |
| Decker House Hotel |
| Decorah Commercial Historic District |
| Decorah Hospital |
| Decorah Municipal Bathhouse and Swimming Pool |
| Decorah Woolen Mill |
| Deering, Nathaniel Cobb and Lucetia Baily, House |
| DeFries House, Barn and Carpenter Shop |
| Delaware County Courthouse |
| Delmar Calaboose |
| Delta Upsilon Chapter House |
| Democrat Building |
| Denison Opera House |
| Denmark Congregational Church |
| Denny, Professor Charles O., House |
| Des Moines Building |
| Des Moines County Court House |
| Des Moines Fire Department Headquarters-Fire Station No. 1 and Shop Building |
| Des Moines Saddlery Company Building |
| Des Moines Township #7 |
| Des Moines Western Railway Freight House |
| Dessaint, Marie Clare, House |
| Dewitt-Harman Archeological Site |
| Dexter Community House |
| Dierks, Peter, House |
| Dillon Memorial |
| Dils-Downer House |
| Dominy, John S., House |
| Donahue Building |
| Downey Savings Bank |
| Downey School |
| Downtown Commercial Historic District |
| Downtown Commercial Historic District |
| Dows Street Historic District |
| Dowtown Perry Historic District |
| Drake, John and Amanda Bigler, House |
| Drake Public Library |
| Drake University Campus Historic District |
| Dr. Salsbury's Laboratories, Main Office and Production Laboratory Building |
| Dubuque Casket Company |
| Dubuque County Courthouse |
| Dubuque Freight House |
| Dubuque Millworking Historic District |
| Dubuque Star Brewery |
| Dubuque YMCA Building |
| Duff Barn |
| Dugan's Saloon |
| Duncan-Duitsman Farm Historic District |
| Duncan, John M., House |
| Dunham, Z. T., Pioneer Stock Farm |
| Dunn, William and Phebe C., House |
| Dunsmore House |
| Dyas, George, House |
| Dyas, William, Barn |
| Eagle Grove Public Library |
| Eagle Point Park Historic District |
| Earle & LeBosquet Block |
| Earlham Public School |
| Early, John and Elizabeth McMurn, House |
| East 14th Street Historic District |
| East Amsterdam School |
| East College Street Historic District |
| East Des Moines Commercial Historic District |
| East Des Moines Industrial Historic District |
| East Hill House and Carraige House |
| East Junior High School |
| East Park Band Shell |
| East Park Historic District |
| Ebeling, Arthur, House |
| Ebeling, Henry, House |
| Economy Advertising Company |
| Edgewood School of Domestic Arts |
| Edinger, Edward, House |
| Edmundson Park Historic District |
| Edwards, Joseph A. and Lydia A., House |
Data from United States Park Service and Wikidata
