District of Columbia - Criteria: C (architecture/engineering)
| Old Stone House |
| Old Woodley Park Historic District |
| Olympia Apartments |
| Oriental Building Association No. 6 Building |
| O Street Market |
| Owens, Isaac, House |
| Page, Thomas Nelson, House |
| Pan American Union |
| Park Road Courts |
| Park Tower |
| Park View School |
| Park Vista and Pine Manor Apartments |
| Peirce Mill |
| Pennsylvania Avenue National Historic Site |
| Pension Building |
| Perna Brothers' Chesapeake Street Houses |
| Petworth Branch Library |
| Petworth Gardens |
| Peyser Building-Security Savings and Commercial Bank |
| Phillips, Duncan, House |
| Pierce-Klingle Mansion |
| Pierce Still House |
| Pink Palace |
| Plymouth, The |
| Plymouth Theater |
| Ponce de Leon Apartment Building |
| Potomac Boat Club |
| President's House, Gallaudet College |
| President's Office, George Washington University |
| President's Park South |
| Prince Hall Masonic Temple |
| Prospect House |
| Quality Hill |
| Quarters A, Washington Navy Yard |
| Quarters B, Washington Navy Yard |
| Railroad Retirement Board Building |
| Randall Junior High School |
| Real Estate Trust Building-Continental Trust Building |
| Renwick Museum |
| Riggs National Bank |
| Riggs National Bank, Washington Loan And Trust Company Branch |
| Riggs-Tompkins Building |
| Ringgold-Carroll House |
| Rock Creek and Potomac Parkway Historic District |
| Rock Creek Church Yard and Cemetery |
| Rock Creek Park Historic District |
| Roosevelt Apartment Building |
| Roosevelt, Theodore, Senior High School |
| Rosedale |
| Saint James Mutual Homes |
| Saul, B.F., Building |
| Scheele-Brown House |
| Schneider Triangle |
| Sears, Roebuck and Company Department Store |
| Second National Bank |
| Sedgwick Gardens |
| Seventh Street Savings Bank |
| Sewall-Belmont House National Historic Site |
| Shaw Junior High School |
| Sheridan-Kalorama Historic District |
| Slater, John Fox, Elementary School |
| Slayton, William L., House |
| Smithsonian Building |
| Social Security Administration Building |
| Southern Aid Society-Dunbar Theater Building |
| Spencer Carriage House and Stable |
| Springland |
| Square 1500 |
| St. Aloysius Catholic Church |
| Steedman-Ray House |
| St. Elizabeths Hospital |
| Stevens, Thaddeus, School |
| St. John's Church |
| St. Mark's Church |
| St. Mary's Episcopal Church |
| St. Matthew's Cathedral And Rectory |
| Stockton Hall |
| Stone, Robert and Lillie May, House |
| St. Paul's Episcopal Church |
| Strivers' Section Historic District |
| Strong, Hattie M., Residence Hall |
| Studio House |
| Suitland Parkway |
| Sulgrave Club |
| Sumner, Charles, School |
| Sun Building |
| Surratt, Mary E., House |
| Syphax, William, School |
| Takoma Park Historic District |
| Temperance Fountain |
| Tenth Precinct Station House |
| Terminal Refrigerating and Warehouse Company |
| Texas Gardens Apartments |
| Theodore Roosevelt Island National Memorial |
| Thomas Jefferson Memorial |
| Tiber Island |
| Tilden Hall |
| Titanic Memorial |
| Tivoli Theater |
| Tower Building |
Data from United States Park Service and Wikidata
