| HIHunter Industries INC | San Marcos | CA | Plastics and Rubber Products Manufacturing326199 | 500+ | ◐ LIKELY ACTIVE |
| NINonlinear INC | San Marcos | CA | Machinery Manufacturing333310 | — | ◐ LIKELY ACTIVE |
| CCCliniqa Corporation | San Marcos | CA | Chemical Manufacturing325413 | — | ◐ LIKELY ACTIVE |
| CCClinqa Corporation | San Marcos | CA | Chemical Manufacturing325413 | — | ◐ LIKELY ACTIVE |
| LSL. Schultz INC Dba Lee's Aquarium & Pet Products | San Marcos | CA | Plastics and Rubber Products Manufacturing326199 | 20-99 | ◐ LIKELY ACTIVE |
| AGAdp Granite & Marble Design | San Marcos | CA | Nonmetallic Mineral Product Manufacturing327991 | — | ◐ LIKELY ACTIVE |
| HIHocking International Laboratories | San Marcos | CA | Chemical Manufacturing325611 | — | ◐ LIKELY ACTIVE |
| 6S622 San Marcos | San Marcos | CA | Food Manufacturing311511 | 100-499 | ◐ LIKELY ACTIVE |
| ALAccu-tech Laser Processing, INC. | San Marcos | CA | Computer and Electronic Product Manufacturing334413 | — | ◐ LIKELY ACTIVE |
| ATAvista Technologies Inc | San Marcos | CA | Chemical Manufacturing325998 | 20-99 | ◐ LIKELY ACTIVE |
| CCCarlsbad Coastal Winery | San Marcos | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| CECreative Electron INC. | San Marcos | CA | Computer and Electronic Product Manufacturing334517 | — | ◐ LIKELY ACTIVE |
| CSCulinary Specialties Inc. | San Marcos | CA | Food Manufacturing311612 | — | ◐ LIKELY ACTIVE |
| EWEv West INC. | San Marcos | CA | Transportation Equipment Manufacturing336320 | — | ◐ LIKELY ACTIVE |
| GEGeneral Electronic Devices, INC. | San Marcos | CA | Computer and Electronic Product Manufacturing334419 | — | ◐ LIKELY ACTIVE |
| KMK-tech Machine, INC. | San Marcos | CA | Fabricated Metal Product Manufacturing332710 | — | ◐ LIKELY ACTIVE |
| LFLa Fleur's Winery | San Marcos | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| MDMACKAY Distillers | San Marcos | CA | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| MMMeadiocrity Mead | San Marcos | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| NENaval Engineering Technology LLC. | San Marcos | CA | Transportation Equipment Manufacturing336611 | 1-19 | ◐ LIKELY ACTIVE |
| OHO'neill Honey Company LLC | San Marcos | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| PSPerfect Soul Whiskey, LLC | San Marcos | CA | Beverage and Tobacco Product Manufacturing312140 | — | ◐ LIKELY ACTIVE |
| RCRaging Cider & Mead Co. | San Marcos | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |
| RCReitz, Charles | San Marcos | CA | Fabricated Metal Product Manufacturing332999 | — | ◐ LIKELY ACTIVE |
| SMSan Marcos | San Marcos | CA | Miscellaneous Manufacturing339113 | 1-19 | ◐ LIKELY ACTIVE |
| TOTwin Oaks Valley Winery | San Marcos | CA | Beverage and Tobacco Product Manufacturing312130 | — | ◐ LIKELY ACTIVE |