OMS
- Doctor of Osteopathic Medicine
- Fantastic Planet
- IBM Db2
- IBM i
- International Liaison Department (Comintern)
- List of Old Marlburians
- Mahdi Army
- Manuel de Oms y de Santa Pau
- Member state of the European Union
- Morphine
- O'Banion Middle School
- OM (disambiguation)
- OPhone
- Oakdale Middle School
- Oakland Middle School
- Odle Middle School
- Odorless Mineral Spirits
- Office Mobile Service
- Old Millfieldians
- Omohyoid muscle syndrome
- Oms en série
- Oms, Pyrénées-Orientales
- Omsætningsafgift
- One Minute Silence
- One Mission Society
- Open Media Commons
- Open Metering System
- Open Music System
- Opsoclonus myoclonus syndrome
- Optical Transport Network
- Oracle Management Server
- Oral and maxillofacial surgery
- Orbital Maneuvering System
- Organisation for the Maintenance of Supplies
- Osceola Middle School
- Outage management system
- Ozaukee Middle School
- Tsentralny Airport
- Workday, Inc.
- World Health Organization