| 2018 | OMAR Y MILTON RODRIGUEZ S.A. |
| 2018 | OMINT |
| 2018 | OMNIMEX S.A. |
| 2018 | ONEINFO CONSULTING |
| 2018 | ONG VAMOS A HACERLO ARGENTINA |
| 2018 | OPEN GALLO |
| 2018 | OPEN GROUP |
| 2018 | OPEN RADIO |
| 2018 | OPTO VISION S.A. |
| 2018 | ORAZUL ENERGY |
| 2018 | ORBIS MERTIG SAIC |
| 2018 | ORGANIZACION SUR AUTOMOTOR SA |
| 2018 | ORGANIZACION TECHINT S.A DIVISION TELECOMUNICACIONES (TESUR) |
| 2018 | ORIGENES |
| 2018 | ORLOSH - ORL MEDIC S.A. |
| 2018 | Oscar Barbieri S.A. |
| 2018 | OSCAR BRUNO ADMINISTRACION DE CONSORCIOS |
| 2018 | OSCRAIA - SURYA |
| 2018 | OSDE - BINARIA SEGUROS |
| 2018 | OSDEPYM |
| 2018 | OSETYA - OBRA SOCIAL DE EMPLEADOS TEXTILES Y AFINES |
| 2018 | OSIAD SALUD |
| 2018 | OSMEDICA |
| 2018 | Osmotica Pharmaceutical |
| 2018 | OSPACA |
| 2018 | OSPIM - OBRA SOCIAL DEL PERSONAL DE LA INDUSTRIA MOLINERA |
| 2018 | OSPOCE |
| 2018 | OSPRERA |
| 2018 | OUTSOURCE SRL |
| 2018 | OXPANE |