| OLOctave Labs LLC | Springfield | OR | — | ◇ UNVERIFIED |
| OLOctave Labs LLC | Pleasant Hill | OR | — | ◇ UNVERIFIED |
| OCOctober CO Chemetal Division | Easthampton | MA | — | ◇ UNVERIFIED |
| OCOcv Control Valves Precision Coatings / Ocv Control Valves Precision Coatings | Tulsa | OK | — | ◇ UNVERIFIED |
| OTO'day Tank and Steel Company | Fargo | ND | — | ◇ UNVERIFIED |
| OIOddello Industries, LLC | Morristown | TN | — | ◇ UNVERIFIED |
| OBOdessa Brandt | Odessa | TX | — | ◇ UNVERIFIED |
| OTOdm Tool & Manufacturing CO | Mccook | IL | — | ◇ UNVERIFIED |
| OEO E a | Aurora | CO | — | ◇ UNVERIFIED |
| OGOec Graphics INC | Oshkosh | WI | — | ◇ UNVERIFIED |
| OFOem Fabricators INC | Neillsville | WI | — | ◇ UNVERIFIED |
| OBOerlikon Balzers | Lake Orion | MI | — | ◇ UNVERIFIED |
| OBOerlikon Balzers Coating USA INC | East Tawas | MI | — | ◇ UNVERIFIED |
| OBOerlikon Balzers Coating Usa, INC | Pell City | AL | — | ◇ UNVERIFIED |
| OBOerlikon Balzers USA INC | Rock Hill | SC | — | ◇ UNVERIFIED |
 Oerlikon Metco (us) INC. | Barboursville | WV | — | ◇ UNVERIFIED |
| OCOgden Chrome Plating & Bumper Exchange | Ogden | UT | — | ◇ UNVERIFIED |
| OCOglivie Company INC the | Astoria | OR | — | ◇ UNVERIFIED |
| OSOhio Steel Industries | Pataskala | OH | — | ◇ UNVERIFIED |
| OOhmstede | La Porte | TX | — | ◇ UNVERIFIED |
 Oil City Iron Works INC | Corsicana | TX | — | ◇ UNVERIFIED |
| OIOilfield-electric-marine INC | Houston | TX | — | ◇ UNVERIFIED |
| OSOil States Industries | Houston | TX | — | ◇ UNVERIFIED |
 Oil States Industries, INC. - Mmc | Houston | TX | — | ◇ UNVERIFIED |
| OSOil States Lampasas | Lampasas | TX | — | ◇ UNVERIFIED |
| OOldcastle | Elmer | NJ | — | ◇ UNVERIFIED |
| OCOld Country Millwork INC | Los Angeles | CA | — | ◇ UNVERIFIED |
| OGOldenburg Group INC | Claremont | NH | — | ◇ UNVERIFIED |
| OSOld School Market INC | Sullivan | IL | — | ◇ UNVERIFIED |
| OGOlen G. Parkhill Owner of Kendallwood Estates | Mahomet | IL | — | ◇ UNVERIFIED |
| OAOlson Aluminum Castings | Rockford | IL | — | ◇ UNVERIFIED |
| OEOlson Engineering | Saint James | MN | — | ◇ UNVERIFIED |
| OSOlympic Steel - Ps&w | Siler City | NC | — | ◇ UNVERIFIED |
| OIOmada International Sumner Division | Sumner | WA | — | ◇ UNVERIFIED |
| OAOmaha Antique & Job Plating CO | Omaha | NE | — | ◇ UNVERIFIED |
| OSOmaha Standard INC | Council Bluffs | IA | — | ◇ UNVERIFIED |
| OSOmaha Standard INC | Hamilton | NJ | — | ◇ UNVERIFIED |
| OCOmco Cast Metals, INC. | Winchester | IN | — | ◇ UNVERIFIED |
| ODOmega Demolition CORP | Rosemont | IL | — | ◇ UNVERIFIED |
| OEOmega Engineering INC | Bridgeport | NJ | — | ◇ UNVERIFIED |
| ONOmega Natchiq New Iberia Facility | New Iberia | LA | — | ◇ UNVERIFIED |
| OMOmni Metals CO INC | Somersworth | NH | — | ◇ UNVERIFIED |
| OPOmni Products INC | Mchenry | IL | — | ◇ UNVERIFIED |
| OHOmnisource Heavy Media | Fort Wayne | IN | — | ◇ UNVERIFIED |
| OSO'neal Steel INC | Houston | TX | — | ◇ UNVERIFIED |
| OSO'neal Steel, INC. | Indianapolis | IN | — | ◇ UNVERIFIED |
| OSO'neal Steel INC I | Greensboro | NC | — | ◇ UNVERIFIED |
| OMOne More Part Dba Omp | Longmont | CO | — | ◇ UNVERIFIED |
| OSOne Source Systems LLC | Vicksburg | MS | — | ◇ UNVERIFIED |
| OOntic | Creedmoor | NC | — | ◇ UNVERIFIED |
| OLOpen Loop Energy Dba Sjs Machine Shop | Farmington | NM | — | ◇ UNVERIFIED |
| OLOpen Loop Energy - Nichols Facility | Safford | AZ | — | ◇ UNVERIFIED |
| OEOpmobility Exterior Usa, LLC | Duncan | SC | — | ◇ UNVERIFIED |
| OPOppenheimer Precision Prod INC | Horsham | PA | — | ◇ UNVERIFIED |
| OCOptical Components | Covina | CA | — | ◇ UNVERIFIED |
| OSOptimas Solutions | Wood Dale | IL | — | ◇ UNVERIFIED |
| OROquawka River Terminal | Gladstone | IL | — | ◇ UNVERIFIED |
| OCOrange County Metal Processing | Fullerton | CA | — | ◇ UNVERIFIED |
| OSOrange State Steel Construction, INC | Pinellas Park | FL | — | ◇ UNVERIFIED |
| OCOrbel CORP | Phillipsburg | NJ | — | ◇ UNVERIFIED |
| OMOrchard Machinery Corporation | Yuba City | CA | — | ◇ UNVERIFIED |
| OOOrchid Orthopedics | Arcadia | CA | — | ◇ UNVERIFIED |
| OOOrchid Orthopedic Solutions | Bridgeport | MI | — | ◇ UNVERIFIED |
| OOOrchid Orthopedics Solutions | Santa Ana | CA | — | ◇ UNVERIFIED |
| OIOregon Iron Works Hidden Way | Vancouver | WA | — | ◇ UNVERIFIED |
| OIOregon Iron Works INC 3001 | Vancouver | WA | — | ◇ UNVERIFIED |
| OPOregon Plating Co., INC. | Portland | OR | — | ◇ UNVERIFIED |
| OIOrion Industries Auburn | Auburn | WA | — | ◇ UNVERIFIED |
| OIOrion Industries & Related Entities | Chicago | IL | — | ◇ UNVERIFIED |
| OMOrion Marine Construction, INC | Tampa | FL | — | ◇ UNVERIFIED |
| OGOrlandi Gear-fraser | Fraser | MI | — | ◇ UNVERIFIED |
| OMOrnamental Metalworks INC | Decatur | IL | — | ◇ UNVERIFIED |
| OIOsage Industries INC | Linn | MO | — | ◇ UNVERIFIED |
| OSOsf St James Hospital | Pontiac | IL | — | ◇ UNVERIFIED |
| OUOsg USA INC | Parma | OH | — | ◇ UNVERIFIED |
| OPOshkosh Plating Technologies INC | Oshkosh | WI | — | ◇ UNVERIFIED |
| OBOsprey Boat Company Metcalf St | Sedro Woolley | WA | — | ◇ UNVERIFIED |
| OSOsram Sylvania Inc, Kentucky Carbide | Madisonville | KY | — | ◇ UNVERIFIED |
| OEOster Enterprises INC | Lemont | IL | — | ◇ UNVERIFIED |
| OTOtis Technology INC | Lyons Falls | NY | — | ◇ UNVERIFIED |
| OSOtten Screw Products Co-otten Screw Products CO | Saint Louis | MO | — | ◇ UNVERIFIED |
| OSOutland Steel, INC. | Caldwell | ID | — | ◇ UNVERIFIED |
| OCOutlaw Customs - 16 Lincoln St, Dover | Dover | DE | — | ◇ UNVERIFIED |
| OGOverton Gear CORP | Addison | IL | — | ◇ UNVERIFIED |
| OMOwen Manufacturing INC | Owen | WI | — | ◇ UNVERIFIED |
| OGOwens-brockway Glass Containers INC | Godfrey | IL | — | ◇ UNVERIFIED |
| OPOwens Plating CO | Rainbow City | AL | — | ◇ UNVERIFIED |
| OWO W Hubbell & Sons | New York Mills | NY | — | ◇ UNVERIFIED |
| OCOwl Creek Boat Works & Storage | Alva | FL | — | ◇ UNVERIFIED |
| OCOwosso Composite | Owosso | MI | — | ◇ UNVERIFIED |
| OIOxbo International CORP | Lynden | WA | — | ◇ UNVERIFIED |
| OMOxford Manufacturing, LLC | Selma | AL | — | ◇ UNVERIFIED |
| OPOxford Plating CO. INC. | Oxford | AL | — | ◇ UNVERIFIED |
| OCOxy-dry CORP | Arlington Heights | IL | — | ◇ UNVERIFIED |
| OIOxylance INC | Birmingham | AL | — | ◇ UNVERIFIED |
| ODOzark Die Casting | Saint Clair | MO | — | ◇ UNVERIFIED |
| OMOzark Mountain Concepts | Rogersville | MO | — | ◇ UNVERIFIED |
| OSOzark Steel Fabricators INC | Farmington | MO | — | ◇ UNVERIFIED |
| OGO-z Gedney | Brooklyn | NY | — | ◇ UNVERIFIED |
| OGOz Gedney Llc/shoemakersville Plt | Shoemakersville | PA | — | ◇ UNVERIFIED |
