| LMLockheed Martin Corporation US CA San Diego 30th St ST E (5578) | San Diego | CA | Transportation Equipment Manufacturing336611 | 1-19 | ◐ LIKELY ACTIVE |
| LMLockheed Martin Corporation US CA San Diego Woden St (1235) | San Diego | CA | Computer and Electronic Product Manufacturing334511 | 20-99 | ◐ LIKELY ACTIVE |
| LLongball | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| LLLucky Line Products, Inc. | San Diego | CA | Miscellaneous Manufacturing339999 | 20-99 | ◐ LIKELY ACTIVE |
| MBMain Building | San Diego | CA | Miscellaneous Manufacturing339112 | 20-99 | ◐ LIKELY ACTIVE |
| MSMaritime Solutions San Diego | San Diego | CA | Transportation Equipment Manufacturing336611 | 500+ | ◐ LIKELY ACTIVE |
| MRMatthew Richards Cellars | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MHMaynus Hardwood Floors, INC | San Diego | CA | Chemical Manufacturing325510 | — | ◐ LIKELY ACTIVE |
| MTMicrochip Technology Inc. Bernardo Center | San Diego | CA | Computer and Electronic Product Manufacturing334413 | 20-99 | ◐ LIKELY ACTIVE |
| MTMilano Trophy, LLC | San Diego | CA | Miscellaneous Manufacturing339950 | — | ◐ LIKELY ACTIVE |
| MBMiltenyi Biotec San Diego | San Diego | CA | Chemical Manufacturing325414 | 20-99 | ◐ LIKELY ACTIVE |
| MRMiramar Ready Mix Plant | San Diego | CA | Nonmetallic Mineral Product Manufacturing327320 | 20-99 | ◐ LIKELY ACTIVE |
| MCMirror CO. LLC | San Diego | CA | Chemical Manufacturing325620 | — | ◐ LIKELY ACTIVE |
| MIMitargos INC. | San Diego | CA | Chemical Manufacturing325412 | — | ◐ LIKELY ACTIVE |
| MCMmt Craft, LLC | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MCMmt Craft, LLC | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MBMolecular Bioproducts INC | San Diego | CA | Chemical Manufacturing325414 | — | ▲ REPORTED CLOSED |
| MBMonserate Biotech, LLC | San Diego | CA | Chemical Manufacturing325414 | — | ◐ LIKELY ACTIVE |
| NWNegociant Winery | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| NINeurelis INC | San Diego | CA | Chemical Manufacturing325412 | — | ◐ LIKELY ACTIVE |
| NENeutronics Enterprises, INC | San Diego | CA | Electrical Equipment, Appliance & Component Manufacturing335312 | — | ◐ LIKELY ACTIVE |
| NCNewtopia Cyder | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| NNgas-f128 | San Diego | CA | Computer and Electronic Product Manufacturing334511 | 500+ | ◐ LIKELY ACTIVE |
| NNgms-f054 | San Diego | CA | Computer and Electronic Product Manufacturing334511 | 500+ | ◐ LIKELY ACTIVE |
| NNgms-f059 | San Diego | CA | Computer and Electronic Product Manufacturing334511 | 500+ | ◐ LIKELY ACTIVE |
| NNgsp-ca75 | San Diego | CA | Transportation Equipment Manufacturing336419 | 100-499 | ◐ LIKELY ACTIVE |
| NUNXP USA, Inc San Diego | San Diego | CA | Computer and Electronic Product Manufacturing334413 | 20-99 | ◐ LIKELY ACTIVE |
| NUNXP USA, Inc Treena St | San Diego | CA | Computer and Electronic Product Manufacturing334413 | 20-99 | ◐ LIKELY ACTIVE |
| OFOberon Fuels - Corporate | San Diego | CA | Chemical Manufacturing325199 | 1-19 | ◐ LIKELY ACTIVE |
| OHOld Harbor Distilling Company | San Diego | CA | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| PSPeace Schools Network | San Diego | CA | Food Manufacturing311999 | — | ◐ LIKELY ACTIVE |
| P1Plant 1 | San Diego | CA | Machinery Manufacturing333111 | 20-99 | ◐ LIKELY ACTIVE |
| PVPremier Ventures International INC | San Diego | CA | Miscellaneous Manufacturing339950 | — | ◐ LIKELY ACTIVE |
| PMProducers Meat & Provision | San Diego | CA | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| PPPure Project | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| QSQorvo - San Diego, CA | San Diego | CA | Computer and Electronic Product Manufacturing334413 | 1-19 | ◐ LIKELY ACTIVE |
| QMQuidelOrtho McKellar | San Diego | CA | Chemical Manufacturing325413 | 1-19 | ◐ LIKELY ACTIVE |
| QRQuidelOrtho Rochester 313 | San Diego | CA | Chemical Manufacturing325413 | 100-499 | ◐ LIKELY ACTIVE |
| RIRadiomobile, INC | San Diego | CA | Computer and Electronic Product Manufacturing334111 | — | ◐ LIKELY ACTIVE |
| RSReBru Spirits | San Diego | CA | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| RIReflective Innovations, LLC | San Diego | CA | Chemical Manufacturing325510 | — | ◐ LIKELY ACTIVE |
| RLReliable-lfc, LLC | San Diego | CA | Chemical Manufacturing325413 | — | ◐ LIKELY ACTIVE |
| RERosano Enterprises LLC | San Diego | CA | Machinery Manufacturing333998 | — | ◐ LIKELY ACTIVE |
| RDRoyal Distributors LLC | San Diego | CA | Plastics and Rubber Products Manufacturing326199 | — | ◐ LIKELY ACTIVE |
| SISaab INC | San Diego | CA | Computer and Electronic Product Manufacturing334419 | — | ◐ LIKELY ACTIVE |
| SDSan Diego Adesa | San Diego | CA | Transportation Equipment Manufacturing336212 | 20-99 | ◐ LIKELY ACTIVE |
| SDSan Diego Cellars | San Diego | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| SDSan Diego, County of | San Diego | CA | Food Manufacturing311991 | — | ◐ LIKELY ACTIVE |
| SDSan Diego Elevator and Lifts, LLC | San Diego | CA | Machinery Manufacturing333921 | — | ◐ LIKELY ACTIVE |
| SDSan Diego- Metropolitan | San Diego | CA | Transportation Equipment Manufacturing336411 | 1-19 | ◐ LIKELY ACTIVE |