| OpusViz | Haryana |
| Oracle Indonesia | Haryana |
| Orange Dice | Kerala |
| Orange Digital Marketing | |
| Orange GPS Solutions Pvt Ltd | Haryana |
| Orange Owl Solutions Pvt Ltd | |
| Orange Softech Pvt Ltd | West Bengal |
| Orange Technolab | Gujarat |
| Orange Techsol | |
| OrangeGlobal | |
| Orangemantra Technology Pvt Ltd | |
| OrangeSkill Technologies Pvt Ltd | |
| Oratech Infosys | |
| Orbit Analytics | Telangana |
| Orbit Edge Tech | |
| Orbit Infotech Pvt Ltd | |
| Orbitsys Technologies Pvt Ltd | Haryana |
| Orbo | Maharashtra |
| Orca Web Technologies | |
| Orchid Pharma Ltd | |
| Orchidblu Solutions | |
| OrciMed Life Sciences | |
| Ordnungskraft Software Development | |
| Oregon Technologies | Kerala |
| Oréll Software Solutions Pvt Ltd | Kerala |
| Oréll Technosystems (India) Pvt Ltd | Kerala |
| Orient Cables (India) Pvt Ltd | Haryana |
| Oriental College of Law | |
| Oriental Education Society | |
| Oriental Education Society's Sanpada College of Commerce & Technology | |
| Oriental Institute of Management | |
| Origin Softwares | |
| Originate Soft Pvt Ltd | |
| Origzo | |
| Orimark Technologies Pvt Ltd | Odisha |
| Orion Electronics | Maharashtra |
| Orion InfoSolutions | |
| Orion Slution | Maharashtra |
| Orios Venture Partners | |
| Orisenc Technologies Pvt Ltd | Tamil Nadu |
| Orisys Infotech | Odisha |
| Orkestra Technologies Pty Ltd | |
| ormexpert.in | Maharashtra |
| OrniSoft | |
| OroPocket | Delhi |
| Orrish IT Solutions | |
| Ors Infotech Pvt Ltd | Gujarat |
| Ortel Communications Ltd | Odisha |
| Ortez Infotech | Kerala |
| Ortmor Agency Pvt Ltd | |