Oklahoma - Area of significance: Architecture
| Caddo Community Building |
| Calvary Baptist Church |
| Cambria School |
| Canadian County Jail |
| Canute Service Station |
| Capitol Hill General Hospital |
| Capitol-Lincoln Terrace Historic District |
| Carey Place Historic District |
| Carpenter, Joseph, House |
| Carrier Congregational Church |
| Carselowey House |
| Cartmill Farm House |
| Casa Blanca |
| Casa Loma Hotel |
| Case, J. I., Plow Works Building |
| Central Fire Station |
| Central High School |
| Central National Bank |
| Central Park Bandstand |
| Champlin, H. H., House |
| Chandler Armory |
| Chandler Bookstore |
| Chandler High School |
| Checotah Business District |
| Checotah MKT Depot |
| Chelsea Motel |
| Cherokee Armory |
| Cherokee Friends Church |
| Cherokee Terrace Apartments |
| Chickasaw National Capitols |
| Chickasha Downtown Historic District |
| Chilocco Indian Agricultural School |
| Choate Cabin |
| Chrislip, H. C., House |
| Cimarron County Courthouse |
| Circle Theater |
| Cities Service Station |
| Cities Service Station #8 |
| Citizens Bank Building |
| Citizens Bank Tower |
| Citizen's State Bank |
| Citizens State Bank |
| Citizens State Bank |
| City Veterinary Hospital |
| Clapp-Cunningham Building |
| Claremore Auto Dealership |
| Claud Collier Chevrolet & Buick Company |
| Clay Hall |
| Clayton High School-Auditorium |
| Cleary, Jack and Helen, House |
| Cleary, John and Helen, House |
| Clem and Cliff Filling Station |
| Cleveland County Courthouse |
| Clinton Armory |
| Clinton-Hardy House |
| Clover Hotel |
| Clyde's Supermarket and T.G.&Y. |
| Coalgate School Gymnasium-Auditorium |
| Cobb Building |
| Colcord Building |
| Cole Chapel School |
| Coleman, George L., Sr., House |
| Coleman Theatre |
| Colony Park Pavilion |
| Comer, C.A., House |
| Conklin House |
| Co-Operative Publishing Company Building |
| Cordell Carnegie Public Library |
| Cosden Building |
| Coss, V. R., House |
| Cotton County Courthouse |
| Cotton-Exchange Building |
| Cottonwood Community Center |
| Covington Jail |
| Craig County Courthouse |
| Crawford House |
| Creek Masonic Lodge No. 226 |
| Crescent School |
| Cronkhite Ranch House |
| Cross, Hamilton, House |
| Crown Heights Historic District |
| Cushing American Legion Building |
| Cushing Armory |
| Czech Hall of Oklahoma City-Lodge Laska |
| Daniel Webster High School Historic District |
| Danner, J.W., House |
| Darr School of Aeronautics Hangar No. 3 |
| Davison Silo |
| Davis Santa Fe Depot |
| Dawson School |
| Dayton School |
| Degnan School |
| Delaware School, District No. 64 |
| Diamond Point Dependent District No. 44 School |
| Dog Creek School |
| Donahoe, Daniel J., House |
| Douglas, H. T., Mansion and Garage |
| Dow Grain Company Elevator |
| Downtown Hobart Historic District |
| Downtown Ponca City Historic District |
Data from United States Park Service and Wikidata
