Maine - Significance region: Local
| Clary Mill |
| Clase, Nicholas P., House |
| Cleftstone |
| Cleveland, Edward L., House |
| Clifford, George F., House |
| Clifford, John D., House |
| Clifford, Nathan, School |
| Cliffwood Hall |
| Clock Farm |
| Clough Meeting House |
| Coburn, John G. |
| Coffin, Stephen, House |
| Colburn House State Historic Site |
| Colburn School |
| Colburn, William, House |
| Colcord Farmstead |
| Cold Spring Farm |
| Cole Block |
| College Block-Lisbon Block |
| College Club Inn |
| Colonial Apartments |
| Colonial Inn |
| Colonial Theater |
| Columbia House |
| Common, The |
| Conant-Sawyer Cottage |
| Concord Haven |
| Congregational Church of Edgecomb |
| Congregational Church of Medway |
| Connor-Bovie House |
| Connors House |
| Continental Mill Housing |
| Conway House |
| Conway Junction Railroad Turntable Site |
| Cony, Gov. Samuel, House |
| Cony High School |
| Coombs, Viola, House |
| Coplin Plantation Schoolhouse |
| CORA F. CRESSEY |
| Corinth Town Hall and Corinthian Lodge #59, I.O.O.F. |
| Corinth Village |
| Cottage on King's Row |
| Cotton-Smith House |
| Cottrill, Matthew, House |
| Cousins Island Chapel |
| Cover Farm |
| Crescent Lodge |
| Crooker, W. D., House |
| Crosby Lodge |
| Crosby Street Historic District |
| Crystal Spring Farm |
| Cuckolds Light Station |
| Cumberland and Oxford Canal |
| Cummings' Guest House |
| Cummings Shoe Factory |
| Cumston Hall |
| Curtis Island Light |
| Curtis, John B., Free Public Library |
| Cushman, Abial, Store |
| Cushman, Charles L., House |
| Cutler Memorial Library |
| Daigle, Jean-Baptiste, House |
| Dalton, Benjamin and Abigail, House |
| Damariscotta Baptist Church |
| Danville Junction Grange #65 |
| Dark Harbor Shop |
| Davis, Dalton Holmes, Memorial Library |
| Davis, John, House |
| Days Ferry Historic District |
| Deacon Hutchins House |
| Deering Estate Barn |
| Deering, J. G., House |
| Deering Memorial United Methodist Church |
| Deering Oaks |
| Deering Street Historic District |
| Deertrees Theatre |
| Dennysville Historic District |
| Devils Head Site |
| Dexter Grist Mill |
| Dexter Universalist Church |
| District #5 School House |
| District No. 1 Schoolhouse |
| District No. 2 School |
| District No. 5 School |
| Division No. 9 School |
| Dix Family Stable |
| Dixmont Corner Church |
| Dixmont Town House |
| Dodge Point Site |
| Dominican Block |
| Donnell, William T., House |
| Donovan-Hussey Farms Historic District |
| Doughty Block |
| Dover-Foxcroft Commercial Historic District |
| Dow Bridge |
| Dreamhome |
| Dresden Brick School House |
| Dresden Town House |
| Drexel Estate |
| Dry Mills School |
Data from United States Park Service and Wikidata
