Pennsylvania - Area of significance: Architecture
| Clear Creek State Park Day Use District |
| Clear Creek State Park Family Cabin District |
| Clearfield Armory |
| Clearfield County Courthouse |
| Clear Spring Mill |
| Cliffs, The |
| Cline's Church of the United Brethren in Christ |
| Clinger-Moses Mill Complex |
| Clinton Street Historic District |
| Cliveden (Chew House) |
| Cloud Home |
| Clow, James Beach, House |
| Coalport Historic District |
| Coatesville Historic District |
| Coatesville Veterans Administration Hospital Historic District |
| Cobbs Creek Automobile Suburb Historic District |
| Cochran, Philip G., Memorial United Methodist Church |
| Codorus Forge and Furnace Historic District |
| Coffee Pot, The |
| Coffeetown Grist Mill |
| Coldbrook Farm |
| Cold Point Historic District |
| Cold Spring Farm |
| Cold Spring Farm Springhouse |
| Colebrook Iron Master's House |
| Colebrook Manor |
| Colerain Forges Mansion |
| Cole, Warren Z., House |
| Colfax Elementary School |
| College Hall, University Of Pennsylvania |
| College Heights Historic District |
| College Hill Residential Historic District |
| College of Physicians of Philadelphia Building |
| Collen Brook Farm |
| Colley, Abel, Tavern |
| Colley, Peter, Tavern and Barn |
| Collins Mansion |
| Colonial Germantown Historic District |
| Colonial Theatre |
| Colton Point State Park |
| Columbia Historic District |
| Columbia Wagon Works |
| Colver-Rogers Farmstead |
| Comerford Theater |
| Comly, Watson, School |
| Commandant's Quarters |
| Commercial Hotel |
| Commodore Historic District |
| Compass Inn |
| Compton and Bloomfield |
| Concord Friends Meetinghouse |
| Concordville Historic District |
| Conestoga Cork Works Building |
| Conewago Chapel |
| Congregational Store |
| Connell Mansion |
| Connellsville Armory |
| Connellsville Union Passenger Depot |
| Connelly, Clifford B., Trade School |
| Connely-Holeman House |
| Conn, John P., House |
| Conroy Junior High School |
| Consolidated Ice Company Factory No. 2 |
| Consumers Cigar Box Company |
| Continental Building |
| Conwell, Russell H., School |
| Conyngham-Hacker House |
| Cook, Anthony Wayne, Mansion |
| Cook, Col. Edward, House |
| Cooke, Jay, Junior High School |
| Cookes House |
| Cook Forest State Park Indian Cabin District |
| Cook Forest State Park River Cabin District |
| Coopersburg Historic District |
| Coplay Cement Company Kilns |
| Coraopolis Armory |
| Coraopolis Railroad Station |
| Corbley, John, Farm |
| Corker Hill |
| Cornwall & Lebanon Railroad Station |
| Corry Armory |
| Corson, Alan W., Homestead |
| Cotton and Maple Streets School |
| Coudersport and Port Allegany Railroad Station |
| Coudersport Historic District |
| Coulsontown Cottages Historic District |
| Coventry Hall |
| Coventryville Historic District |
| Cowans Gap State Park Family Cabin District |
| Cox, Hewson, House |
| Craft, Gershom, House |
| Cramond |
| Craven Hall |
| Crawford, John Minor, House |
| Crawford, William, House |
| Cree, William, House |
| Creighton, Thomas, School |
| Crook Farm |
| Crossan, Kennedy, School |
| Crown Can Company Building |
Data from United States Park Service and Wikidata
