| O'CONNOR-LEETZ FUNERAL HOME PC | Business | 060008400 | ELGIN | NOT RENEWED | Verify |
| O'DONNELL & CO LTD | Business | 060004587 | CHICAGO | NOT RENEWED | Verify |
| O'DONNELL-BARTZ-SCHULTZ FUNERAL HOME LTD | Business | 060002258 | CHICAGO | ACTIVE | Verify |
| O'HARE DENTAL GROUP PC | Business | 060006351 | CHICAGO | ACTIVE | Verify |
| O'KEEFE & ASSOCIATES PC | Business | 060007957 | ORLAND PARK | NOT RENEWED | Verify |
| OABROOK HRT, P.C. | Business | 060012983 | OAKBROOK TERRACE | NOT RENEWED | Verify |
| OAK BROOK CENTRE FOR HEALTH LTD | Business | 060010860 | CHICAGO | NOT RENEWED | Verify |
| OAK BROOK DENTAL ASSOCIATES LTD | Business | 060005359 | OAK BROOK | NOT RENEWED | Verify |
| OAK BROOK DENTAL GROUP PC | Business | 060005415 | OAK BROOK | NOT RENEWED | Verify |
| OAK BROOK REPORTING LTD | Business | 060005789 | LYONS | NOT RENEWED | Verify |
| OAK CHIROPRACTIC LTD | Business | 060005713 | ARLINGTON HEIGHTS | NOT RENEWED | Verify |
| OAK DENTAL & ASSOCS LTD | Business | 060006254 | CHICAGO | NOT RENEWED | Verify |
| OAK FOREST ANIMAL CLINIC PC | Business | 060000942 | OAK FOREST | NOT RENEWED | Verify |
| OAK FOREST ANIMAL CLINIC PC | Business | 060004810 | OAK FOREST | NOT RENEWED | Verify |
| OAK FOREST ANIMAL CLINIC PC | Business | 060006653 | OAK FOREST | NOT RENEWED | Verify |
| OAK LAWN DENTAL CARE PC | Business | 060011536 | OAK LAWN | NOT RENEWED | Verify |
| OAK LAWN DENTAL GROUP PC | Business | 060005369 | OAK LAWN | NOT RENEWED | Verify |
| OAK LAWN OPTOMETRIC GROUP PC | Business | 060005859 | OAK LAWN | NOT RENEWED | Verify |
| OAK PARK ANIMAL HOSPITAL LTD | Business | 060000499 | OAK PARK | ACTIVE | Verify |
| OAK PARK CARDIOLOGIST GROUP LTD | Business | 060005124 | HINSDALE | NOT RENEWED | Verify |
| OAK PARK DENTAL GROUP PC | Business | 060011523 | CHICAGO | NOT RENEWED | Verify |
| OAK PARK MEDICAL SERVICES P.C | Business | 060011682 | OAK PARK | NOT RENEWED | Verify |
| OAK PARK ORAL SURGERY PC | Business | 060010649 | OAK PARK | NOT RENEWED | Verify |
| OAK PARK PODIATRY ASSOCIATES LTD | Business | 060003318 | OAK PARK | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011131 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012383 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011381 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011410 | BLUE ISLAND | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011382 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012398 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012411 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012809 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012810 | HARWOOD HEIGHTS | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011130 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012417 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011592 | ROCKFORD | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011643 | ROCKFORD | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012811 | STREAMWOOD | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011380 | BERWYN | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011383 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011542 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060011644 | CHICAGO | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012402 | CHICAGO HEIGHTS | NOT RENEWED | Verify |
| OAK STREET HEALTH PHYSICIANS GROUP, PC | Business | 060012808 | AURORA | NOT RENEWED | Verify |
| OAK VIEW DENTAL GROUP LTD | Business | 060007604 | OAK FOREST | NOT RENEWED | Verify |
| OAKBROOK COSMETIC & GENERAL DENTAL AFFILIATES LTD | Business | 060007429 | GLEN CARBON | NOT RENEWED | Verify |
| OAKBROOK ENDODONITIC ASSOCIATES LTD | Business | 060009021 | PLAINFIELD | ACTIVE | Verify |
| OAKBROOK ENDODONTIC ASSOCIATES LTD | Business | 060009066 | NAPERVILLE | ACTIVE | Verify |
| OAKBROOK ENDODONTIC ASSOCS LTD | Business | 060001074 | OAK BROOK | NOT RENEWED | Verify |
| OAKBROOK ENDODONTIC ASSOICATES LTD | Business | 060009031 | OAK BROOK | ACTIVE | Verify |