Illinois - Significance region: Local
| Pulaski Park and Fieldhouse |
| Pure Oil Station |
| Purple, George E., House |
| Quigley Preparatory Seminary |
| Quinby, Ivory, House |
| Quincy National Cemetery |
| Quincy Northwest Historic District |
| Ramova Theater |
| Ramsey, Charles N., and Herry E. Weese House |
| Randecker's Hardware Store |
| Ransom Water Tower |
| Ravenswood Manor Historic District |
| Ravisloe Country Club |
| Raymond M. Hilliard Center Historic District |
| Raymond Park Apartments |
| Reed, Mrs. Kersey Coates, House |
| Reef House |
| Rees, Harriet F., House |
| Rehnstrom, August and Margaretha, House |
| Reid House |
| Reimbold, William J., House |
| Reorganized Church of Jesus Christ of Latter Day Saints |
| Ricker, Nathan C., House |
| Ridgeland-Oak Park Historic District |
| Riis, Jacob A., Park |
| Rippon-Kinsella House |
| Ritzman, William, House |
| Riverside Park Bandshell |
| Riverview Historic District |
| Robbins Park Historic District |
| Robertson, John, Jr., House |
| Roberts, William H., House |
| Robinson-Bonnett Inn |
| Robinson House |
| Robinson, J. L., General Store |
| Robinwood |
| Rochelle Downtown Historic District |
| Roche, Martin-John Tait House |
| Rockford Brass Works |
| Rockford Elk's Lodge #64 |
| Rockford Gas Light & Coke Fitting and Meter Shops Building |
| Rockford Morning Star Building |
| Rockford Woman’s Club |
| Rock Island Depot and Freight House |
| Rock Island Lines Passenger Station |
| Rogers, Col. Matthew, Building |
| Rogers, Orson, House |
| Rogers Park Manor Bungalow Historic District |
| Rohrbough, Calendar, House |
| Rollo Congregational United Church of Christ |
| Roosevelt Junior High School |
| Root-Badger House |
| Ropp-Grabill House |
| Ross, Harvey Lee, House |
| Ross, Joseph, House |
| Rothschild, A. M., & Company Store |
| Route 66 by Carpenter Park |
| Route 66 South of Lake Springfield |
| Royalton Hotel |
| Roycemore School |
| Royer, Joseph W., House and Ella Danely Cottage |
| Roytek, Richard, House |
| Rozek, Theodore, House |
| Ruebel Hotel |
| Rutherford, Dr. Hiram, House and Office |
| Rutter Store |
| Ryerson, Edward L., Area Historic District |
| Sala Apartment Building |
| Salem Baptist Church |
| Saline County Poor Farm |
| Sauganash Historic District |
| Scales Mound Historic District |
| Schertz, Joseph, House |
| Schiller, Alfred A.,House |
| Schlitz Brewery-Tied House |
| Schlosser, Frank, Complex |
| Schoenhofen Brewery Historic District |
| Schorsch Irving Park Gardens Historic District |
| Schudel No. 2 Site |
| Schurz, Carl, High School |
| Scott, Lyman, House |
| Scott, Matthew T., House |
| Scoville Place |
| Scutt, Hiram B., Mansion |
| Sears, Albert H., House |
| Sesser Opera House |
| Seventh Street Commercial Historic District |
| Shabbona Hotel |
| Shaky Shelter Site |
| Shastid, John, House |
| Shaw-Van Gilder House |
| Sheridan Park Historic District |
| Sherman Park |
| Sherrard Banking Company |
| Shiloh College |
| Shoreland Hotel |
| Shoreline Apartments |
| Shriver Farmstead |
| Shriver House |
| Sigma Alpha Epsilon Fraternity House |
Data from United States Park Service and Wikidata
