| Decatur County Memorial Hospital | Greensburg | IN |
| Decatur Strawboard | Decatur | IN |
| Decatur Strawboard | Marion | IN |
| Decca Manufacturing | Richmond | IN |
| Dekalb Memorial Hospital | Auburn | IN |
| Delamar Copper Refining | Hammond | IN |
| Delco Electronics | Kokomo | IN |
| Delco Electronics | Muncie | IN |
| Delphi Planing Mill & Hook | Delphi | IN |
| Deluxe Check Printers | Indianapolis | IN |
| Denison Hotel | Indianapolis | IN |
| DePaul University | Greencastle | IN |
| Design & Manufacturing | Richmond | IN |
| Detroit Diesel | Indianapolis | IN |
| Detroit Steel Products | Morristown | IN |
| Diamond Match | Wabash | IN |
| Diamond Veneer & Lumber | Shelbyville | IN |
| Dirilyte Company Of America | Kokomo | IN |
| Dodge Manufacturing | Mishawaka | IN |
| Dominion Energy | Hammond | IN |
| Doughnut Company Of America | Noblesville | IN |
| Dow Chemical | Gary | IN |
| Dow Chemical | Indianapolis | IN |
| Dow Chemical | Zionsville | IN |
| Dresser Power | Terre Haute | IN |
| Drewry's U.S.A. | South Bend | IN |
| Drinking Water Treatment | Rockville | IN |
| Duncan Electric Manufacturing | Lafayette | IN |
| Dunlop | Shelbyville | IN |
| Dunn Memorial Hospital | Bedford | IN |
| DuPont | Covington | IN |
| DuPont | East Chicago | IN |
| DuPont | Dana | IN |
| DuPont | Charlestown | IN |
| Dwyer Products | Michigan City | IN |
| Dynamic Power | Ossian | IN |
| Eagle Knitting | Elkhart | IN |
| Eagle Valley Generating Station | Martinsville | IN |
| Eastern Asylum | Richmond | IN |
| Eastern Indiana Hospital For Insane | Richmond | IN |
| East Mobile High School | Indianapolis | IN |
| East Noble School | Kendallville | IN |
| Eaton Canning | Eaton | IN |
| Eaton Yale & Towne | Connersville | IN |
| E.B. Lanman | East Chicago | IN |
| Ebner Ice & Cold Storage | Vincennes | IN |
| E.C. Atkins & Company | Indianapolis | IN |
| Economist Plow | South Bend | IN |
| Education & General Classroom Building | Muncie | IN |
| Edwardsport | Plainfield | IN |
