| OAKBROOK ORTHODONTIC | Business | 060004856 | OAK BROOK | NOT RENEWED | Verify |
| OAKLEY GETHMANN AND OSTRAND LTD | Business | 060001904 | EVANSTON | CANCELLED | Verify |
| OAKS HINES FUNERAL HOME LTD | Business | 060001864 | CANTON | NOT RENEWED | Verify |
| OAKWOOD CLINIC LTD | Business | 060005419 | LIBERTYVILLE | NOT RENEWED | Verify |
| OBAYYA CHENNAREDDY MD PC | Business | 060003865 | NORTHBROOK | NOT RENEWED | Verify |
| OCC JUDGE, P.C. | Business | 060012834 | CHICAGO | ACTIVE | Verify |
| OCCU-SPORT PHYS THERAPY OF ST CHARLES PC | Business | 060008281 | ST CHARLES | NOT RENEWED | Verify |
| OCCU-SPORT PHYSICAL THERAPY | Business | 060007763 | OAK LAWN | NOT RENEWED | Verify |
| OCCU-SPORT PHYSICAL THERAPY OF ORLAND PARK PC | Business | 060007739 | ORLAND PARK | NOT RENEWED | Verify |
| OCCUPATIONAL AND HAND THERAPY LTD | Business | 060004521 | ORLAND PARK | NOT RENEWED | Verify |
| OCCUPATIONAL AND HAND THERAPY LTD | Business | 060010940 | BLUE ISLAND | NOT RENEWED | Verify |
| OCCUPATIONAL CLINICAL PSYCHOLOGISTS LTD | Business | 060002943 | WILMETTE | NOT RENEWED | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011199 | DARIEN | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060012422 | BEDFORD PARK | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011041 | SCHAUMBURG | CLOSED | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011089 | LINCOLNWOOD | NOT RENEWED | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011090 | MOLINE | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011098 | ELK GROVE VILLAGE | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011083 | WHEELING | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011085 | AURORA | NOT RENEWED | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060012087 | CHICAGO | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011086 | BLOOMINGDALE | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060012321 | CHICAGO | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011080 | CHICAGO | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011082 | CHICAGO | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011087 | BRIDGEVIEW | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011079 | MORTON GROVE | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011081 | CHICAGO | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011200 | ELK GROVE VILLAGE | NOT RENEWED | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060012322 | SCHILLER PARK | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060011088 | FRANKLIN PARK | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060012320 | BELLWOOD | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060013138 | WAUKEGAN | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060013137 | WAUKEGAN | ACTIVE | Verify |
| OCCUPATIONAL HEALTH CENTERS OF ILLINOIS, P.C. | Business | 060013240 | ELK GROVE VILLAGE | ACTIVE | Verify |
| OCCUPATIONAL THERAPY | Business | 060005473 | LOVES PARK | NOT RENEWED | Verify |
| OCEAN DENTAL GROUP LTD | Business | 060011608 | BOLINGBROOK | NOT RENEWED | Verify |
| OCULAR SERVICES PC | Business | 060003970 | WAUKEGAN | CANCELLED | Verify |
| OEHMIG INTERIOR DESIGN LTD | Business | 060005932 | ST CHARLES | NOT RENEWED | Verify |
| OEHRLEIN & OEHRLEIN PC | Business | 060009528 | MOUNT PROSPECT | NOT RENEWED | Verify |
| OFELIA POD DMD PC | Business | 060009479 | CRYSTAL LAKE | NOT RENEWED | Verify |
| OFELIA POD DMD PC | Business | 060009570 | CRYSTAL LAKE | NOT RENEWED | Verify |
| OFFICE ANESTHESIOLOGY & DENTAL CONSULTANTS PC | Business | 060010388 | OAKBROOK TERRACE | ACTIVE | Verify |
| OFFICE OF CPA AND ASSOCIATES LTD | Business | 060010527 | CHICAGO | CANCELLED | Verify |
| OFFICER FUNERAL HOME | Business | 060004098 | EAST ST LOUIS | NOT RENEWED | Verify |
| OGDEN N MUNROE DDS LTD | Business | 060004366 | SPRINGFIELD | NOT RENEWED | Verify |
| OGOREK AND ASSOCS LTD | Business | 060002316 | PARK RIDGE | NOT RENEWED | Verify |
| OHLENDORF & TREGO PC | Business | 060006105 | AMBOY | NOT RENEWED | Verify |
| OLD ORCHARD DENTAL GROUP PC | Business | 060011207 | SKOKIE | NOT RENEWED | Verify |
| OLD TOWN DENTAL ASSOCIATES LTD | Business | 060000591 | CRETE | NOT RENEWED | Verify |