| Richmond Manufactured Gas Plant | Richmond | IN |
| Richmond Municipal Power Plant | Richmond | IN |
| Richmond Power & Light | Richmond | IN |
| Richmond Street & Interurban Railway | Richmond | IN |
| Richmond Street & Interurban Railway | Terre Haute | IN |
| Rieke Metal Products | Auburn | IN |
| Riley Tar & Chemical | Indianapolis | IN |
| Rising Sun | Rising Sun | IN |
| R.J. Oil & Refinery | Princeton | IN |
| Rochester Electric Light Heat & Power | Rochester | IN |
| Rochester High School | Indianapolis | IN |
| Rock Island Refining | Zionsville | IN |
| Rock Island Refining | Indianapolis | IN |
| Rockport Power Plant | Rockport | IN |
| Rockport Water Works | Rockport | IN |
| Rockville High School | Rockville | IN |
| Rockwell Manufacturing | Gary | IN |
| Rockwood Manufacturing | Indianapolis | IN |
| Roger High School | Michigan City | IN |
| Rogers Markets Store | Fort Wayne | IN |
| Rolling Mill Refinery | Gary | IN |
| Rolls Royce | Indianapolis | IN |
| Roots Connersville | Richmond | IN |
| Rose Fuel & Materials | South Bend | IN |
| Roseland Motel | Roseland | IN |
| Rose Polytechnic Institute | Terre Haute | IN |
| Ross Brothers & Whistler | Wabash | IN |
| Ross Gear Division | Lafayette | IN |
| Rossiter, MacGovern & Company | Kokomo | IN |
| Rossville Union Distillery | Lawrenceburg | IN |
| Rostone | Lafayette | IN |
| Roxana Petroleum | East Chicago | IN |
| Royal Inn | South Bend | IN |
| R. R. Donnelley | Warsaw | IN |
| RR Donnelley | Warsaw | IN |
| Rubber Regenerating | Mishawaka | IN |
| Rubbers Synthetic | Gary | IN |
| Rub-No-More | Fort Wayne | IN |
| Rude Brothers Manufacturing | Liberty | IN |
| Ruoff & Sons Incenerator Enclosures | Fort Wayne | IN |
| Saint Anthony Hospital | Terre Haute | IN |
| Saint Dometrios Greek Church | Hammond | IN |
| Saint Elizabeth Hospital | Lafayette | IN |
| Saint Francis College | Fort Wayne | IN |
| Saint Francis Convent | Mishawaka | IN |
| Saint Francis Hospital | Mishawaka | IN |
| Saint Francis Hospital | Indianapolis | IN |
| Saint Francis Hospital | Beech Grove | IN |
| Saint Francis Infirmary | Mishawaka | IN |
| Saint John Baptist Catholic School | Fort Wayne | IN |
