By customer
- Oakland County, Michigan
- Oberbank AG
- OCBC Bank
- OCH Regional Medical Center
- Odyssey Logistics & Technology Corporation
- Odyssey Transportation & Logistics Corporation
- OfficeMax
- OhioHealth
- Oklahoma Department of Human Services
- Oldmac
- OLM Systems
- OMERS
- Omnicom Group Inc.
- Omron Europe
- OMV Gas & Power GmbH
- Oncor Electric
- Oncor
- One of the largest banks in Southeast Asia
- OneTree Solutions
- Online Backup Company
- Online content provider
- OpenLogix Corp.
- Open Universities Australia
- Orange Business Services
- ORGA
- Oriflame Cosmetics
- Orvis
- OTP Bank
- Oxxio
