Illinois - Criteria: A (event)
| Portage Park Bungalow Historic District |
| Potter and Barker Grain Elevator |
| Power Farmstead |
| Prairie Avenue District |
| Princeton Chapter House |
| Princeton North Main Street Historic District |
| Princeton South Main Street-Courthouse Square Historic District |
| Proctor Building |
| Proctor, John C., Recreation Center |
| Produce Terminal Cold Storage Company Building |
| Pullman Historic District |
| Putnam County Courthouse |
| Quincy National Cemetery |
| Quinn Chapel of the A.M.E. Church |
| Railway Exchange Building |
| Randecker's Hardware Store |
| Ransom Water Tower |
| Ravenswood Manor Historic District |
| Raymond M. Hilliard Center Historic District |
| Raymond Park Apartments |
| Red Covered Bridge |
| Rehnstrom, August and Margaretha, House |
| Reid Murdoch Building |
| Reimbold, William J., House |
| Reorganized Church of Jesus Christ of Latter Day Saints |
| Ridge Boulevard Apartments |
| Ridge Grove |
| Ridge Historic District |
| Ridgeland-Oak Park Historic District |
| Ridge Manor |
| Riis, Jacob A., Park |
| Riverbank Laboratories |
| Riverside Landscape Architecture District |
| Riverside Park Bandshell |
| Riverview Historic District |
| Robbins Park Historic District |
| Robinson-Bonnett Inn |
| Robinson, J. L., General Store |
| Rochelle Downtown Historic District |
| Rock Island Arsenal |
| Rock Island Depot and Freight House |
| Rock Island Lines Passenger Station |
| Rock Island National Cemetery |
| Rogers, Col. Matthew, Building |
| Rogers Park Manor Bungalow Historic District |
| Rookwood Apartments |
| Room 405, George Herbert Jones Laboratory, The University of Chicago |
| Rose Hotel |
| Rosenwald Apartment Building |
| Rubens Rialto Square Theater |
| Ruebel Hotel |
| Rutter Store |
| Ryan Round Barn |
| Salem Baptist Church |
| Saline County Poor Farm |
| Saline Springs |
| Sandwich City Hall |
| Sauganash Historic District |
| Scales Mound Historic District |
| Schlosser, Frank, Complex |
| Schoenhofen Brewery Historic District |
| Schorsch Irving Park Gardens Historic District |
| Schultz, Raymond, Round Barn |
| Schulze Baking Company Plant |
| Scott Field Historic District |
| Scott, Lyman, House |
| Scott, Matthew T., House |
| Scott-Vrooman House |
| Sears, Roebuck and Company Complex |
| Sesser Opera House |
| Seventh Street Commercial Historic District |
| Seville Bridge |
| Shakespeare Garden |
| Shedd, John G., Aquarium |
| Shelbyville Historic District |
| Sheridan Plaza Hotel |
| Sheridan Square Apartments |
| Sherman Park |
| Shiloh College |
| Shoreland Hotel |
| Shriver Farmstead |
| Sigma Alpha Epsilon Fraternity House |
| Singer Building |
| Smith, A. Herr and E. E., Public Library |
| Soldiers and Sailors Memorial Hall |
| Soldier's Monument |
| Soldiers' Monument |
| Soulsby Service Station |
| South Henderson Church and Cemetery |
| South Loop Printing House District |
| South Park Manor Historic District |
| South Shore Country Club |
| South Side Community Art Center |
| South Side German Historic District |
| South Side School |
| South Water Market |
| Spiegel Office Building |
| Sprague's Super Service |
| Spring Valley House-Sulfur Springs Hotel |
| Standard Oil Gasoline Station |
Data from United States Park Service and Wikidata
