OBS
- Chevrolet C/K (fourth generation)
- Coop Obs!
- L'Obs
- OBS (South Korean broadcaster)
- OBS Studio
- OBS! (magazine)
- OBSS (disambiguation)
- Obstetrics and gynaecology
- Ocean-bottom seismometer
- Océ
- Off-balance-sheet
- Office of Boating Safety
- Oita Broadcasting System
- Olympic Broadcasting Services
- On Basilisk Station
- One Buck Short
- Open Build Service
- Oporto British School
- Optical burst switching
- Optus Broadband Satellite
- Orange Belt Stages
- Orange Blossom Special (song)
- Orange Business Services
- Organic brain syndrome
- Organisation breakdown structure
- Organization for Black Struggle
- Outward Bound
- Outward Bound Singapore
- TV licence
- VHF omnidirectional range