| PPrimient | Dayton, OH | Chemical Manufacturing325199 | 20–99 | ◐ LIKELY ACTIVE |
| PSPrinting Service Company | Miamisburg, OH | Printing and Related Support Activities323111 | 20–99 | ◐ LIKELY ACTIVE |
| PPProto Plastics Inc. | Tipp City, OH | Plastics and Rubber Products Manufacturing326121 | 20–99 | ◐ LIKELY ACTIVE |
| PSP&R Specialty, Inc. | Piqua, OH | Wood Product Manufacturing321999 | 20–99 | ◐ LIKELY ACTIVE |
| QSQQE Summit, LLC | Beavercreek, OH | Computer and Electronic Product Manufacturing334419 | 100–499 | ◐ LIKELY ACTIVE |
| RPRack Processing Company, Inc. | Moraine, OH | Fabricated Metal Product Manufacturing332812 | 20–99 | ◐ LIKELY ACTIVE |
| RKResonetics Kettering | Kettering, OH | Miscellaneous Manufacturing339112 | 100–499 | ◐ LIKELY ACTIVE |
| RPRoss Products LLC | Xenia, OH | Paper Manufacturing322220 | — | ◐ LIKELY ACTIVE |
| STSalley Tool & Die CO. LLC | Beavercreek, OH | Fabricated Metal Product Manufacturing332999 | — | ◐ LIKELY ACTIVE |
| SAS and G Artisan Distillery, LLC | Yellow Springs, OH | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| SAScarlet Aerospace Technologies LTD. | Fairborn, OH | Transportation Equipment Manufacturing336413 | — | ◐ LIKELY ACTIVE |
| SISew-eurodrive, INC. | Troy, OH | Electrical Equipment, Appliance & Component Manufacturing335312 | 100–499 | ◐ LIKELY ACTIVE |
| SFShearer's Foods - Dayton | Moraine, OH | Food Manufacturing311919 | 1–19 | ◐ LIKELY ACTIVE |
| SIShiloh Industries INC | Dayton, OH | Electrical Equipment, Appliance & Component Manufacturing335999 | — | ◐ LIKELY ACTIVE |
| SCSilver Creek Stables Riding Center, LLC | Xenia, OH | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| STSilver Tool INC | Miamisburg, OH | Fabricated Metal Product Manufacturing332710 | — | ◐ LIKELY ACTIVE |
| SCSnyder Concrete Products - Yard 3 | Troy, OH | Nonmetallic Mineral Product Manufacturing327331 | 1–19 | ◐ LIKELY ACTIVE |
| SCSnyder Concrete Products - Yard 5 | Moraine, OH | Nonmetallic Mineral Product Manufacturing327331 | 20–99 | ◐ LIKELY ACTIVE |
| SISpectron INC | Dayton, OH | Computer and Electronic Product Manufacturing334419 | — | ◐ LIKELY ACTIVE |
| SASpinnaker a MACTAC Company | Troy, OH | Plastics and Rubber Products Manufacturing326112 | 100–499 | ◐ LIKELY ACTIVE |
| SGSpring Grove Foods Inc. | Miamisburg, OH | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| SOSteered Optics LLC | Dayton, OH | Computer and Electronic Product Manufacturing334511 | — | ◐ LIKELY ACTIVE |
| SMStolle Machinery - Dayton | Dayton, OH | Machinery Manufacturing333517 | 20–99 | ◐ LIKELY ACTIVE |
| SHStoney Hill Farm & Winery | Miamisburg, OH | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| SCSugarCreek Ciderworks | Bellbrook, OH | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| SPSugarcreek Plant 141 | Bellbrook, OH | Nonmetallic Mineral Product Manufacturing327320 | 20–99 | ◐ LIKELY ACTIVE |
| SISuperion Inc | Xeina, OH | Machinery Manufacturing333515 | 1–19 | ◐ LIKELY ACTIVE |
| SISwihart Industries, Inc. | Dayton, OH | Fabricated Metal Product Manufacturing332710 | 20–99 | ◐ LIKELY ACTIVE |
| TCTaylor Comms - Dayton OH - 0116-OHDA1 | Dayton, OH | Printing and Related Support Activities323111 | 20–99 | ◐ LIKELY ACTIVE |
| TPTech Products Corp | Miamisburg, OH, OH | Plastics and Rubber Products Manufacturing326291 | 20–99 | ◐ LIKELY ACTIVE |
| TCTelamon Corporation - Dayton | Dayton, OH | Transportation Equipment Manufacturing336320 | 20–99 | ◐ LIKELY ACTIVE |
| TDTeledyne Defense Electronics, LLC | Miamisburg, OH | Fabricated Metal Product Manufacturing332993 | — | ◐ LIKELY ACTIVE |
| TQTeledyne - Qioptiq - Miamisburg | Miamisburg, OH | Fabricated Metal Product Manufacturing332993 | 100–499 | ◐ LIKELY ACTIVE |
| TLTerapico LLC | Beavercreek, OH | Computer and Electronic Product Manufacturing334413 | — | ◐ LIKELY ACTIVE |
| TOTextum OPCO, LLC (2133 Lyons) | Miamisburg, OH | Electrical Equipment, Appliance & Component Manufacturing335991 | 20–99 | ◐ LIKELY ACTIVE |
| THThe Hyland Machine Company | Dayton, OH | Fabricated Metal Product Manufacturing332721 | 20–99 | ◐ LIKELY ACTIVE |
| TKThe Killer Brownie Company | Miamisburg, OH | Food Manufacturing311812 | 100–499 | ◐ LIKELY ACTIVE |
| TPThink Patented Inc. | Miamisburg, OH | Printing and Related Support Activities323111 | 20–99 | ◐ LIKELY ACTIVE |
| TLTipolar, LLC | Xenia, OH | Computer and Electronic Product Manufacturing334516 | — | ◐ LIKELY ACTIVE |
Tom Smith Industries, Inc. | Englewood, OH | Plastics and Rubber Products Manufacturing326199 | 20–99 | ◐ LIKELY ACTIVE |
| TOTroy Operations | Troy, OH | Machinery Manufacturing333992 | 100–499 | ◐ LIKELY ACTIVE |
| TPTroy Plant | Troy, OH | Fabricated Metal Product Manufacturing332321 | 500+ | ◐ LIKELY ACTIVE |
| TPTroy Plant 151 | Troy, OH | Nonmetallic Mineral Product Manufacturing327320 | 20–99 | ◐ LIKELY ACTIVE |
| TNTuck N Red's Spirits & Wine | Yellow Springs, OH | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| TOTuken's Orchard & Farm Market | West Alexandria, OH | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| TITwist Inc. Plant 10 | Jamestown, OH | Fabricated Metal Product Manufacturing332613 | 1–19 | ◐ LIKELY ACTIVE |
| TPTwist Plant 3 | Xenia, OH | Fabricated Metal Product Manufacturing332613 | 20–99 | ◐ LIKELY ACTIVE |
| TPTwist Plant 6 | Xenia, OH | Fabricated Metal Product Manufacturing332813 | 1–19 | ◐ LIKELY ACTIVE |
| TPTwist Plants 1 and 7 | Jamestown, OH | Fabricated Metal Product Manufacturing332613 | 100–499 | ◐ LIKELY ACTIVE |
| TPTwist Plants 5 and 9 | Jamestown, OH | Fabricated Metal Product Manufacturing332613 | 20–99 | ◐ LIKELY ACTIVE |