| o Quad Industries Inc. MI | Manufacturing | 1 | $109,600 | — |
| O & H Danish Bakery INC WI | Retail Trade | 0 | — | A |
| O & H Martinez Construction Corp TN | Construction | 0 | — | A |
| O & M MULTI-TRADE INC PA | Construction | 0 | — | F |
| O & S Research, Inc. NJ | Manufacturing | 0 | — | A |
| O and B Community Homes MI | Healthcare & Social Assistance | 0 | — | A |
| O C House SF, LLC dba The Old Clam House CA | — | 0 | — | — |
| O C WELCH FORD LINCOLN INC SC | Retail Trade | 0 | — | C |
| O Leary Construction, LLC PA | Construction | 0 | — | A |
| O Positiv, Inc. CA | Retail Trade | 1 | $295,000 | — |
| O&D Electric Corp. NY | Construction | 0 | — | A |
| O&E MATIAS ELECTRICAL SERVICE, LLC. HI | Construction | 0 | — | A |
| O&F Machine Products MO | Manufacturing | 0 | — | C |
| O&G Industries, Inc. CT | Construction | 0 | — | F |
| O&H Danish Bakery, Inc. WI | Manufacturing | 1 | $58,240 | F |
| O&k American Corp. IL | Manufacturing | 0 | — | F |
| O&k American Corp. IN | Manufacturing | 0 | — | F |
| O&M Halyard TX | Transportation & Warehousing | 0 | — | A |
| O&M Industries CA | Construction | 0 | — | A |
| O&M, Inc. TN | Professional & Technical Services | 0 | — | A |
| O'Brien & Gere Inc. of North America NY | Construction | 0 | — | A |
| O'Brien and Company LLC OR | Construction | 0 | — | D |
| O'Brien Auto Group OR | Retail Trade | 0 | — | B |
| O'Brien Auto Group WA | Retail Trade | 0 | — | A |
| O'Brien Bros. Inc IL | Construction | 0 | — | F |
| O'Brien Construction Company MI | Construction | 0 | — | A |
| O'Brien Dental Lab, Inc. OR | Manufacturing | 0 | — | F |
| O'Brien Interiors Group MI | Construction | 0 | — | A |
| O'Brien Mechanical, Inc. II CA | Construction | 0 | — | A |
| O'Brien Orchards Inc. WA | Agriculture & Forestry | 0 | — | F |
| O'Brien Steel Erectors, Inc. CA | Construction | 0 | — | F |
| O'Brien Steel Erectors, Inc. HI | Construction | 0 | — | A |
| O'Brien Steel Service Co. IL | Wholesale Trade | 0 | — | F |
| O'Brien Steel Service Co. WI | Wholesale Trade | 0 | — | A |
| O'Brien&Company OR | Construction | 0 | — | D |
| O'Brien's Market CA | Retail Trade | 0 | — | C |
| O'Bryant Electric Inc. CA | Construction | 0 | — | B |
| O'Cain, Inc. FL | Construction | 0 | — | D |
| O'Connell Electric Company, Inc NY | Construction | 0 | — | A |
| O'Connell Landscape Maintenance CA | Administrative & Waste Services | 0 | — | A |
| O'Connor Company IA | Wholesale Trade | 0 | — | A |
| O'Connor Company KS | Wholesale Trade | 0 | — | A |
| O'Connor Company MO | Wholesale Trade | 0 | — | A |
| O'Connor Company NE | Wholesale Trade | 0 | — | C |
| O'Connor Company OK | Wholesale Trade | 0 | — | A |
| O'Connor Company SD | Wholesale Trade | 0 | — | A |
| O'Connor Corporation MA | Construction | 0 | — | A |
| O'Connor Hospital CA | — | 0 | — | — |
| O'Connor Hospital NY | Healthcare & Social Assistance | 2 | $80,517 | — |
| O'Connor Mechanical Corp NY | Construction | 0 | — | A |