| CSCatalent San Diego | San Diego | CA | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| COCatalina Offshore Products, INC. | San Diego | CA | Food Manufacturing311710 | — | ◇ UNVERIFIED |
| CCCathedral Church of St. Paul | San Diego | CA | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
| CTCb Therapeutics | San Diego | CA | Computer and Electronic Product Manufacturing334516 | — | ◇ UNVERIFIED |
| CACell Applications INC | San Diego | CA | Chemical Manufacturing325414 | — | ◇ UNVERIFIED |
 Central Admixture Pharmacy Services INC | San Diego | CA | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| CMCentral Marble Supply | San Diego | CA | Nonmetallic Mineral Product Manufacturing327991 | — | ◇ UNVERIFIED |
| CHCeramic Heights | San Diego | CA | Nonmetallic Mineral Product Manufacturing327110 | — | ◇ UNVERIFIED |
| CICes INC Staging at Nasni | San Diego | CA | Transportation Equipment Manufacturing336611 | — | ◇ UNVERIFIED |
| CCCha Ca Nha Trang | San Diego | CA | Food Manufacturing311710 | — | ◇ UNVERIFIED |
| CKCharles Koll Jewellers | San Diego | CA | Miscellaneous Manufacturing339910 | — | ◇ UNVERIFIED |
| CMCharles Maynard Lucey and Norma Lacarra Lucey | San Diego | CA | Transportation Equipment Manufacturing336611 | — | ◇ UNVERIFIED |
| CCCharter Communications | San Diego | CA | Transportation Equipment Manufacturing336390 | — | ◇ UNVERIFIED |
| CSChemcia Scientific LLC | San Diego | CA | Chemical Manufacturing325199 | — | ◇ UNVERIFIED |
| CIChemcyte INC | San Diego | CA | Chemical Manufacturing325411 | — | ◇ UNVERIFIED |
| CPChem Pro Laboratory, INC. | San Diego | CA | Chemical Manufacturing325199 | — | ◇ UNVERIFIED |
| CEChicks Electric Motor Service | San Diego | CA | Electrical Equipment, Appliance & Component Manufacturing335312 | — | ◇ UNVERIFIED |
| CRChris Ruddy Surfboards | San Diego | CA | Miscellaneous Manufacturing339920 | — | ◇ UNVERIFIED |
| COChurch of the Nazarene Mid City | San Diego | CA | Transportation Equipment Manufacturing336350 | — | ◇ UNVERIFIED |
| CHCity Heights Realty, LLC | San Diego | CA | Machinery Manufacturing333921 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Transportation Equipment Manufacturing336350 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| COCity of San Diego | San Diego | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| CDClareo Designs INC | San Diego | CA | Nonmetallic Mineral Product Manufacturing327215 | — | ◇ UNVERIFIED |
| CDClarity Design INC | San Diego | CA | Computer and Electronic Product Manufacturing334111 | — | ◇ UNVERIFIED |
 Clean Air Power INC. | San Diego | CA | Transportation Equipment Manufacturing336399 | — | ◇ UNVERIFIED |
| CHClean Harbors | San Diego | CA | Machinery Manufacturing333415 | — | ◇ UNVERIFIED |
| CClearstory | San Diego | CA | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| CCCleator Corporation | San Diego | CA | Furniture and Related Product Manufacturing337122 | — | ◇ UNVERIFIED |
| CPCline Property | San Diego | CA | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| CRCmc Rebar - Ca - San Diego | San Diego | CA | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| CACnc Aztec | San Diego | CA | Fabricated Metal Product Manufacturing332510 | — | ◇ UNVERIFIED |
| CACnc Aztec Precision Machining INC. | San Diego | CA | Transportation Equipment Manufacturing336390 | — | ◇ UNVERIFIED |
| CACoast Aggregates | San Diego | CA | Nonmetallic Mineral Product Manufacturing327331 | — | ◇ UNVERIFIED |
| CCCoastal Coatings INC | San Diego | CA | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| CMCoastal Marine Services, INC. | San Diego | CA | Transportation Equipment Manufacturing336611 | — | ◇ UNVERIFIED |
| CTCoastar Therapeutics INC | San Diego | CA | Chemical Manufacturing325414 | — | ◇ UNVERIFIED |
| CWCoastline Woodwork CO | San Diego | CA | Furniture and Related Product Manufacturing337110 | — | ◇ UNVERIFIED |
| CICognionics, INC. | San Diego | CA | Nonmetallic Mineral Product Manufacturing327991 | — | ◇ UNVERIFIED |
| CCCohuhd Costar | San Diego | CA | Computer and Electronic Product Manufacturing334515 | — | ◇ UNVERIFIED |
| CPColcris Productions | San Diego | CA | Paper Manufacturing322220 | — | ◇ UNVERIFIED |
| CPColcris Productions Dba Creative Coatings | San Diego | CA | Paper Manufacturing322222 | — | ◇ UNVERIFIED |
| CColdpack | San Diego | CA | Plastics and Rubber Products Manufacturing326112 | — | ◇ UNVERIFIED |
| CPCommercial Press | San Diego | CA | Printing and Related Support Activities323113 | — | ◇ UNVERIFIED |
