| 2021 | OMINT |
| 2021 | OMNIMEX S.A. |
| 2021 | ONCO LIFE SRL |
| 2021 | ONG AMIGOS DEL RIO |
| 2021 | ONG. CORAZON CARMESI |
| 2021 | OPEN GALLO |
| 2021 | OPTO VISION S.A. |
| 2021 | ORBIS MERTIG SAIC |
| 2021 | ORGANIZACION SUR AUTOMOTOR SA |
| 2021 | Orien S.A. |
| 2021 | Oscar Barbieri S.A. |
| 2021 | OSCAR BRUNO ADMINISTRACION DE CONSORCIOS |
| 2021 | OSDOP - OBRA SOCIAL DE DOCENTES PARTICULARES |
| 2021 | Osmotica Pharmaceutical |
| 2021 | OSPACA |
| 2021 | OSPIM - OBRA SOCIAL DEL PERSONAL DE LA INDUSTRIA MOLINERA |
| 2021 | OSPRERA |
| 2021 | OUTSOURCE SRL |
| 2021 | OXY NET S.A. |
| 2021 | PALLARO HNOS. S.A. |
| 2021 | PAMATEX |
| 2021 | PAMI |
| 2021 | PAMI - SANTA MARIA 3494 |
| 2021 | PAMI - ARCHIVOS |
| 2021 | PAMI - FARMALINK |
| 2021 | PAMI - ITUZAINGO |
| 2021 | PAMI - LUJAN |
| 2021 | PAMI - RECURSOS FISICOS |
| 2021 | PAMI 3 |
| 2021 | PAMPA ENERGIA |