Massachusetts - Area of significance: Architecture
| City Hall Historic District |
| City Hall Historic District |
| City Stable and Garage |
| Claflin, Adams, House |
| Claflin-Richards House |
| Claflin School |
| Clapp, George, House |
| Clapp Houses |
| Clapp, Lucius, Memorial |
| Clark-Eames House |
| Clarke-Glover Farmhouse |
| Clarke, Pitt, House |
| Clarke School for the Deaf Historic District |
| Clark House |
| Clark Houses |
| Clark-Northrup House |
| Clark University |
| Cleale, Joseph, House |
| Cleveland Ledge Light Station |
| Cliff Cottage |
| Clifford-Warren House |
| Cliff, Z. E., House |
| Clinton African Methodist Episcopal Zion Church |
| Clough, Benjamin F., House |
| Cloverden |
| Cluett Peabody & Company |
| Coast Guard Motor Lifeboat CG 36500 |
| Cobb, George, House |
| Cobb Memorial Library |
| Cochran,Jehiel, House |
| Codding Farm, The |
| Coddington School |
| Codman Building |
| Codman Square District |
| Coffin, Jethro, House |
| Cogan, Bernard, House |
| Cogan, James, House |
| Coggin, Gilman, House |
| Cogswell's Grant |
| Cohannet Mill No. 3 |
| Cohasset Common Historic District |
| Coker, Benjamin, House |
| Colburn, Gilbert, House |
| Colburn, Sarah Foster, House |
| Colburn School |
| Colburn School-High Street Historic District |
| Colby Hall |
| Colby, Samuel, House |
| Cole, Benjamin, House |
| Cole, E. Merritt, House |
| Cole House |
| Collins Cottages Historic District |
| Collins, Frederick, House |
| Collins, William, House |
| Colonial Beacon Gas Station |
| Colonial Block |
| Colony Historic District |
| Colrain Center Historic District |
| Colton's Block |
| Columbia Road-Bellevue Street Historic District |
| Columbia Road-Devon Street Historic District |
| Columbia Road-Strathcona Road Historic District |
| Columbus Avenue and Bragdon Street Historic District |
| Comfort Station |
| Comins-Wall House |
| Commanding Officer's Quarters, Watertown Arsenal |
| Common District |
| Common Historic District |
| Commonwealth Avenue Historic District |
| Commonwealth Avenue Historic District |
| Commonwealth Pier Five |
| Commonwealth Shoe and Leather Co. |
| Community House |
| Community Memorial Hospital |
| Company F State Armory |
| Compton Building |
| Conant, Exercise, House |
| Concord Armory |
| Concord Square Historic District |
| Congregation Adath Jeshurun |
| Congregation Agudath Shalom |
| Congregational Church |
| Congregational Church of West Stockbridge |
| Congress Street Fire Station |
| Conkey-Stevens House |
| Connell, William M., School |
| Conventual Church of St. Mary and St. John |
| Converse Memorial Building |
| Conway Center Historic District |
| Cook, A. E., House |
| Cook, Asa M., House |
| Cook, Thomas, House |
| Cook, William, House |
| Coolidge, Josiah, House |
| Coolidge School |
| Cooper-Davenport Tavern Wing |
| Cooper-Frost-Austin House |
| Copeland, Samuel, House |
| Copp's Hill Terrace |
| Coram Shipyard Historic District |
Data from United States Park Service and Wikidata
