| Short J R Milling | Mount Vernon | IN |
| Sibley Machine & Foundry | South Bend | IN |
| Simmons Service Station | Indianapolis | IN |
| Simmons Warehouse | Indianapolis | IN |
| Sims Bayon Sludge Treatment | East Chicago | IN |
| Sinclair Manufacturing | Merrillville | IN |
| Sinclair Oil | East Chicago | IN |
| Sinclair Oil | Whiting | IN |
| Singer | South Bend | IN |
| Sisters Of Providence | Saint Marys | IN |
| Skyline Homes | Elkhart | IN |
| Slick's Family Washing | Fort Wayne | IN |
| Sliger & Holloway | Indianapolis | IN |
| Sludge Plant | Fort Wayne | IN |
| Sluntsky Plbg & Htg | Notre Dame | IN |
| Smith Cabinet Manufacturing | Salem | IN |
| Smith Chevrolet | La Porte | IN |
| Smurfit-Stone Container | Wabash | IN |
| Snider Preserve | Fairmount | IN |
| Snyder Sheet Metal | Lafayette | IN |
| Socony Mobil Oil | East Chicago | IN |
| Sohio | Brooklyn | IN |
| South Bend Beverage & Ice Association | South Bend | IN |
| South Bend Brewing | South Bend | IN |
| South Bend Iron Works | South Bend | IN |
| South Bend Pump | South Bend | IN |
| South Bend Range | South Bend | IN |
| South Bend Supply | South Bend | IN |
| South Bend Toy Manufacturing | South Bend | IN |
| South Bend Wagon Works | South Bend | IN |
| South Bend Wood Parts | South Bend | IN |
| South Calhoun School | Fort Wayne | IN |
| Southeast Development | Indianapolis | IN |
| South Eastern Hospital for the Insane | Madison | IN |
| Southern Clay | Paris | IN |
| Southern Heights School | Fort Wayne | IN |
| Southern Hospital For Insane | Madison | IN |
| Southern Indiana Gas & Electric | Evansville | IN |
| Southern Indiana Gas & Electric | Newburgh | IN |
| Southern Indiana Power | Williams | IN |
| Southern Indiana Railway | Bedford | IN |
| Southern Indiana Railway | Terre Haute | IN |
| Southern Railway | Princeton | IN |
| Southlake Shopping Mall | Merrillville | IN |
| South Of Southgate Shopping Center | Fort Wayne | IN |
| Southport High School | Indianapolis | IN |
| South Wayne School | Fort Wayne | IN |
| Southwest Feed Mill | Loogootee | IN |
| South Wind Division Of Stewart Warner | Indianapolis | IN |
| Southwood School | Wabash | IN |
