| APArmorcast Products CO | Ontario | CA | Plastics and Rubber Products Manufacturing326199 | — | ◇ UNVERIFIED |
| AIArral Ind | Ontario | CA | Machinery Manufacturing333415 | — | ◇ UNVERIFIED |
| ATArrow Truck Bodies & Equip INC | Ontario | CA | Transportation Equipment Manufacturing336211 | — | ◇ UNVERIFIED |
| AFArt's Forklift Repair INC | Ontario | CA | Machinery Manufacturing333924 | — | ◇ UNVERIFIED |
| ALAryzta, LLC | Ontario | CA | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| ADAstro Display Company INC | Ontario | CA | Furniture and Related Product Manufacturing337215 | — | ◇ UNVERIFIED |
| ACAtrium Corporation Dba Superior Windows & Doors | Ontario | CA | Fabricated Metal Product Manufacturing332321 | — | ◇ UNVERIFIED |
| ATAuburn Tile | Ontario | CA | Nonmetallic Mineral Product Manufacturing327332 | — | ◇ UNVERIFIED |
| ASAvalon Shutters INC | Ontario | CA | Wood Product Manufacturing321911 | — | ◇ UNVERIFIED |
| ADAxxess Door, Corp. | Ontario | CA | Fabricated Metal Product Manufacturing332321 | — | ◇ UNVERIFIED |
| ACAz Countertops, INC | Ontario | CA | Nonmetallic Mineral Product Manufacturing327991 | — | ◇ UNVERIFIED |
| ACAz Countertops, INC. | Ontario | CA | Nonmetallic Mineral Product Manufacturing327991 | — | ◇ UNVERIFIED |
| ABAzteca's Bakery | Ontario | CA | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| BPBakery Pan Services INC. | Ontario | CA | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| BCBausman & CO | Ontario | CA | Furniture and Related Product Manufacturing337215 | — | ◇ UNVERIFIED |
| BCBausman & Company | Ontario | CA | Furniture and Related Product Manufacturing337122 | — | ◇ UNVERIFIED |
| BCBausman & Company | Ontario | CA | Furniture and Related Product Manufacturing337122 | — | ◇ UNVERIFIED |
| BCBci Coca-cola Bottling Company of Los Angeles | Ontario | CA | Beverage and Tobacco Product Manufacturing312111 | — | ◇ UNVERIFIED |
| BDB & D Litho California INC | Ontario | CA | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| BSBear State Pump & Equip CORP | Ontario | CA | Machinery Manufacturing333911 | — | ◇ UNVERIFIED |
| BEB E D Solutions L L C | Ontario | CA | Miscellaneous Manufacturing339910 | — | ◇ UNVERIFIED |
| BVBeer Valley Brewing Company, LLC | Ontario | OR | Beverage and Tobacco Product Manufacturing312120 | — | ◇ UNVERIFIED |
| BIBertolini Incorporated | Ontario | CA | Machinery Manufacturing333994 | — | ◇ UNVERIFIED |
| BIBest Ink and Thread | Ontario | CA | Printing and Related Support Activities323113 | — | ◇ UNVERIFIED |
| BIBioscrip Infusion Services INC | Ontario | CA | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| BIBishamon Industries CORP | Ontario | CA | Machinery Manufacturing333924 | — | ◇ UNVERIFIED |
| BOBlack Oak Foundry | Ontario | CA | Fabricated Metal Product Manufacturing332323 | — | ◇ UNVERIFIED |
| BBBoston Beef House INC | Ontario | OR | Food Manufacturing311611 | — | ◇ UNVERIFIED |
| BIBp Industries Incorporated | Ontario | CA | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| BDBravo Design and Fabrication LLC | Ontario | CA | Fabricated Metal Product Manufacturing332710 | — | ◇ UNVERIFIED |
| BCBruce Caballero | Ontario | CA | Petroleum and Coal Products Manufacturing324191 | — | ◇ UNVERIFIED |
| BBBusy Bee Tooling | Ontario | CA | Machinery Manufacturing333514 | — | ◇ UNVERIFIED |
| CICaleche Investment LLC | Ontario | CA | Food Manufacturing311991 | — | ◇ UNVERIFIED |
| CDCaltrans District 8 Ea 08-0e33u4 | Ontario | CA | Wood Product Manufacturing321114 | — | ◇ UNVERIFIED |
| CSCapital Steel Products | Ontario | CA | Fabricated Metal Product Manufacturing332323 | — | ◇ UNVERIFIED |
| CCaraustar | Ontario | CA | Paper Manufacturing322130 | — | ◇ UNVERIFIED |
| CICargill INC | Ontario | CA | Food Manufacturing311225 | — | ◇ UNVERIFIED |
| CCCarny Chem CORP | Ontario | CA | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| CICastle Industries INC. of Ca. | Ontario | CA | Fabricated Metal Product Manufacturing332322 | — | ◇ UNVERIFIED |
| CHCatalyst Hydraulic Machining | Ontario | CA | Computer and Electronic Product Manufacturing334511 | — | ◇ UNVERIFIED |
| CDC & D Plastics | Ontario | CA | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| CZC&d Zodiac Inc./zodiac Aerospace | Ontario | CA | Computer and Electronic Product Manufacturing334511 | — | ◇ UNVERIFIED |
 Certified Aviation Services LLC | Ontario | CA | Transportation Equipment Manufacturing336413 | — | ◇ UNVERIFIED |
| CPChander Prakash Mittal and Rekha Chander Mittal, Trustees of The Mittal Family T | Ontario | CA | Transportation Equipment Manufacturing336390 | — | ◇ UNVERIFIED |
| CBCherry Blossom, J Diaz & E Diaz, INC | Ontario | CA | Furniture and Related Product Manufacturing337122 | — | ◇ UNVERIFIED |
| CLChristian Life LLC | Ontario | CA | Machinery Manufacturing333511 | — | ◇ UNVERIFIED |
| CICinco Iron Works INC | Ontario | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| CSCitistaff Solutions, INC. | Ontario | CA | Furniture and Related Product Manufacturing337127 | — | ◇ UNVERIFIED |
| COCity of Ontario | Ontario | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| COCity of Ontario Fire Department | Ontario | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
