| MMMansfield Metal Solutions LLC | Ontario | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| MAMartinez and Sons Auto Repair | Ontario | CA | Apparel Manufacturing315210 | — | ◇ UNVERIFIED |
| MHMaterial Handling Solutions | Ontario | CA | Machinery Manufacturing333922 | — | ◇ UNVERIFIED |
| MQMaximum Quality Metal Products INC | Ontario | CA | Machinery Manufacturing333415 | — | ◇ UNVERIFIED |
| MGMcgarec Gear Machine INC | Ontario | CA | Fabricated Metal Product Manufacturing332117 | — | ◇ UNVERIFIED |
| MBMelvin Baltodano | Ontario | CA | Fabricated Metal Product Manufacturing332323 | — | ◇ UNVERIFIED |
| MWMelvin Wrought Iron & Ornamental | Ontario | CA | Fabricated Metal Product Manufacturing332323 | — | ◇ UNVERIFIED |
| MHMercy House Living Center | Ontario | CA | Transportation Equipment Manufacturing336350 | — | ◇ UNVERIFIED |
| MIMidlab, INC. | Ontario | CA | Chemical Manufacturing325612 | — | ◇ UNVERIFIED |
| MJMike Jenkins | Ontario | CA | Petroleum and Coal Products Manufacturing324191 | — | ◇ UNVERIFIED |
| MAMikronpmp Aeropace | Ontario | CA | Miscellaneous Manufacturing339991 | — | ◇ UNVERIFIED |
| MPMission Plastics INC | Ontario | CA | Plastics and Rubber Products Manufacturing326121 | — | ◇ UNVERIFIED |
| MGMondelez Global LLC | Ontario | CA | Food Manufacturing311821 | — | ◇ UNVERIFIED |
| MRMoonlight R&d LLC. | Ontario | CA | Furniture and Related Product Manufacturing337127 | — | ◇ UNVERIFIED |
| MEM&r Engineering CO Dba S&h Glenco Manufacturing | Ontario | CA | Fabricated Metal Product Manufacturing332721 | — | ◇ UNVERIFIED |
| MPMueller Plastics CORP INC | Ontario | CA | Plastics and Rubber Products Manufacturing326199 | — | ◇ UNVERIFIED |
| MKMuhammad Khan and Nahid Khan | Ontario | CA | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| MEMvi Engineering & Manufacturing INC | Ontario | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| MPMyers Power Products INC | Ontario | CA | Electrical Equipment, Appliance & Component Manufacturing335313 | — | ◇ UNVERIFIED |
| NANap Asset Holding LTD Dba Nap Gladu | Ontario | CA | Plastics and Rubber Products Manufacturing326199 | — | ◇ UNVERIFIED |
| NCNational Cng and Fleet Service | Ontario | CA | Transportation Equipment Manufacturing336320 | — | ◇ UNVERIFIED |
| NMNational Metal Fabrication INC | Ontario | CA | Fabricated Metal Product Manufacturing332999 | — | ◇ UNVERIFIED |
| NPNeste Polyester | Ontario | CA | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| NSNet Shapes INC | Ontario | CA | Primary Metal Manufacturing331512 | — | ◇ UNVERIFIED |
| NSNet Shapes INC | Ontario | CA | Primary Metal Manufacturing331512 | — | ◇ UNVERIFIED |
| NFNew Flyer of America | Ontario | CA | Transportation Equipment Manufacturing336120 | — | ◇ UNVERIFIED |
| NINew Indy Jv LLC Dba Proactive Packaging & Display | Ontario | CA | Paper Manufacturing322211 | — | ◇ UNVERIFIED |
| NINew- Indy Ontario, LLC | Ontario | CA | Paper Manufacturing322120 | — | ◇ UNVERIFIED |
| NINicca Investments, Inc. | Ontario | CA | Fabricated Metal Product Manufacturing332812 | — | ◇ UNVERIFIED |
| NPNorthern Pacific Airways, INC. | Ontario | CA | Fabricated Metal Product Manufacturing332912 | — | ◇ UNVERIFIED |
| OIOakwood Interiors Site | Ontario | CA | Furniture and Related Product Manufacturing337122 | — | ◇ UNVERIFIED |
| OPOldcastle Precast, INC. | Ontario | CA | Nonmetallic Mineral Product Manufacturing327390 | — | ◇ UNVERIFIED |
| OFOme9a Franchises LLC | Ontario | OH | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| O7Ontario 76 | Ontario | CA | Petroleum and Coal Products Manufacturing324110 | — | ◇ UNVERIFIED |
| OAOntario Airport | Ontario | OR | Machinery Manufacturing333911 | — | ◇ UNVERIFIED |
| OCOntario Castings, Performance Aluminum Products, Reeds Patterns & Molds, R&S ... | Ontario | CA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| OEOntario Extrusions, INC. | Ontario | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| ONOntario Neon CO INC | Ontario | CA | Miscellaneous Manufacturing339950 | — | ◇ UNVERIFIED |
| OROntario Ranch | Ontario | CA | Machinery Manufacturing333111 | — | ◇ UNVERIFIED |
| OBOrange Boxer Operations LLC Kap Stone Paper and Packaging Ontario Box | Ontario | CA | Paper Manufacturing322120 | — | ◇ UNVERIFIED |
| OCOrange County Erectors, INC. | Ontario | CA | Fabricated Metal Product Manufacturing332311 | — | ◇ UNVERIFIED |
| OROthon R. Martinez and Sabrina R. Martinez | Ontario | CA | Miscellaneous Manufacturing339116 | — | ◇ UNVERIFIED |
| OWO W Lee Comapny INC | Ontario | CA | Furniture and Related Product Manufacturing337124 | — | ◇ UNVERIFIED |
| OROzawa R & D INC | Ontario | OR | Machinery Manufacturing333911 | — | ◇ UNVERIFIED |
| PGPacific Graphic Supply | Ontario | CA | Machinery Manufacturing333244 | — | ◇ UNVERIFIED |
| PRPacific Rebar INC | Ontario | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| PPParagon Partners | Ontario | CA | Nonmetallic Mineral Product Manufacturing327999 | — | ◇ UNVERIFIED |
| PCParty City CORP Dba Halloween City Store #8014 | Ontario | CA | Miscellaneous Manufacturing339910 | — | ◇ UNVERIFIED |
| PJPatel & Joshi Hospitality CORP Dba Americas Best Value Inn & Suites on | Ontario | CA | Nonmetallic Mineral Product Manufacturing327110 | — | ◇ UNVERIFIED |
| PPPby Plastics | Ontario | CA | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
