| CDCurtiss-Wright DS, Inc. d/b/a Curtiss-Wright C5ISR Data Solutions | Fairborn, OH | Computer and Electronic Product Manufacturing334511 | 20–99 | ◐ LIKELY ACTIVE |
| DGDAP Global Inc. - Tipp City | Tipp City, OH | Chemical Manufacturing325510 | 20–99 | ◐ LIKELY ACTIVE |
| DCDAYST Contech Engineered Solutions LLC | Huber Heights, OH | Nonmetallic Mineral Product Manufacturing327331 | 1–19 | ◐ LIKELY ACTIVE |
| DTDay-tec Tool & Manufacturing INC | Miamisburg, OH | Machinery Manufacturing333514 | — | ◐ LIKELY ACTIVE |
| DDayton | Miamisburg, OH | Transportation Equipment Manufacturing336390 | 20–99 | ◐ LIKELY ACTIVE |
| DDayton | Dayton, OH | Wood Product Manufacturing321214 | 20–99 | ◐ LIKELY ACTIVE |
| DBDayton Barrel Works | Dayton, OH | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| DODayton OH | Dayton, OH | Wood Product Manufacturing321920 | 20–99 | ◐ LIKELY ACTIVE |
| DODayton OH Panel | Vandalia, OH | Wood Product Manufacturing321215 | 1–19 | ◐ LIKELY ACTIVE |
| DPDayton Progress Corperation | Dayton, OH | Machinery Manufacturing333517 | 100–499 | ◐ LIKELY ACTIVE |
| DEDeban Enterprises, INC. | Dayton, OH | Computer and Electronic Product Manufacturing334513 | — | ◐ LIKELY ACTIVE |
| DADefense and Systems UD EPISCenter | Dayton, OH | Transportation Equipment Manufacturing336412 | 100–499 | ◐ LIKELY ACTIVE |
| DADefense and Systems Vandalia OH | Vandalia, OH | Transportation Equipment Manufacturing336320 | 100–499 | ◐ LIKELY ACTIVE |
| DMDRT MPS- Dayton | Dayton, OH | Machinery Manufacturing333514 | 100–499 | ◐ LIKELY ACTIVE |
| DPDRT Precision- Miamisburg | Miamisburg, OH | Fabricated Metal Product Manufacturing332710 | 20–99 | ◐ LIKELY ACTIVE |
Eastman Kodak Company- Dayton, OH | Dayton, OH | Chemical Manufacturing325992 | 100–499 | ◐ LIKELY ACTIVE |
| ECEaton Compressor & Fabrication, INC | Englewood, OH | Machinery Manufacturing333912 | — | ◐ LIKELY ACTIVE |
| ELEdfa, LLC | Dayton, OH | Fabricated Metal Product Manufacturing332710 | — | ◐ LIKELY ACTIVE |
| EIElectro-line INC | Dayton, OH | Computer and Electronic Product Manufacturing334419 | — | ◐ LIKELY ACTIVE |
| ETEpix Tube Company, Inc. | Dayton, OH | Primary Metal Manufacturing331110 | 100–499 | ◐ LIKELY ACTIVE |
| EDEquipment Depot Ohio, Inc - Dayton | Dayton, OH | Machinery Manufacturing333924 | 20–99 | ◐ LIKELY ACTIVE |
| ECEvenflo Company Inc. - MSB | Miamisburg, OH | Furniture and Related Product Manufacturing337125 | 20–99 | ◐ LIKELY ACTIVE |
| EIExel Inc. | Dayton, OH | — | — | ◐ LIKELY ACTIVE |
| EMExito Manufacturing LLC | Beavercreek, OH | Fabricated Metal Product Manufacturing332710 | — | ◐ LIKELY ACTIVE |
| F0Factory - 01 | Dayton, OH | Plastics and Rubber Products Manufacturing326199 | 20–99 | ◐ LIKELY ACTIVE |
| FPFairborn Plant 163 | Fairborn, OH | Nonmetallic Mineral Product Manufacturing327320 | 20–99 | ◐ LIKELY ACTIVE |
| FPFC Precision Inc. | Dayton, OH | Machinery Manufacturing333514 | 20–99 | ◐ LIKELY ACTIVE |
| FTFirst Tool CORP. | Dayton, OH | Fabricated Metal Product Manufacturing332322 | — | ◐ LIKELY ACTIVE |
| FRFlat Rock Spirits LLC | Fairborn, OH | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| FEFondriest Environmental, INC. | Fairborn, OH | Computer and Electronic Product Manufacturing334513 | — | ▲ REPORTED CLOSED |
| FUFukuvi USA, INC. | Huber Heights, OH | Machinery Manufacturing333249 | 20–99 | ◐ LIKELY ACTIVE |
| GAGe Aviation Systems LLC | Dayton, OH | Computer and Electronic Product Manufacturing334419 | — | ◐ LIKELY ACTIVE |
| GAGeneral Atomics Aeronautical Systems, INC. | Beavercreek, OH | Transportation Equipment Manufacturing336411 | — | ◐ LIKELY ACTIVE |
| GOGermantown, OH | Germantown, OH | Machinery Manufacturing333241 | 100–499 | ◐ LIKELY ACTIVE |
| HAHAHN Automation Group US, Inc. DA 2 | Miamisburg, OH | Machinery Manufacturing333519 | 20–99 | ◐ LIKELY ACTIVE |
| HAHAHN Automation Group US, Inc. HQ | Miamisburg, OH | Machinery Manufacturing333519 | 20–99 | ◐ LIKELY ACTIVE |
| HBHall Brothers Distillery | Dayton, OH | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| HAHartzell Air Movement | Piqua, OH | Machinery Manufacturing333413 | 100–499 | ◐ LIKELY ACTIVE |
Hartzell Propeller at Hartzell Airfield | Piqua, OH | Transportation Equipment Manufacturing336413 | 20–99 | ◐ LIKELY ACTIVE |
| HDHayner Distilling & Importing INC. | Troy, OH | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| HSHexagonal Scientific Laboratory LLC | Dayton, OH | Electrical Equipment, Appliance & Component Manufacturing335991 | — | ◐ LIKELY ACTIVE |
| HPHonest Pour Distilling LLC | Troy, OH | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| HFHPC Fire Inspired | Miamisburg, OH | Machinery Manufacturing333414 | 20–99 | ◐ LIKELY ACTIVE |
| ISIDC Spring, OH | Piqua, OH | Fabricated Metal Product Manufacturing332613 | 20–99 | ◐ LIKELY ACTIVE |
Indiana Oxygen Company-Dayton | Dayton, OH | Chemical Manufacturing325120 | 1–19 | ◐ LIKELY ACTIVE |
| ICIndian Creek Distillery LLC | New Carlisle, OH | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| ICIndian Creek Fabricators INC. | Tipp City, OH | Fabricated Metal Product Manufacturing332313 | — | ◐ LIKELY ACTIVE |
| IEIndustrial Estates - Yard 1 | Moraine, OH | Nonmetallic Mineral Product Manufacturing327331 | 1–19 | ◐ LIKELY ACTIVE |
| IMIntegrated Manufacturing Dayton OH Unison | Dayton, OH | Transportation Equipment Manufacturing336412 | 100–499 | ◐ LIKELY ACTIVE |
| IMIntegrated Manufacturing DCCDayton | Dayton, OH | Transportation Equipment Manufacturing336412 | 20–99 | ◐ LIKELY ACTIVE |