OHA
- Community Action Agencies
- DHS Office of Health Affairs
- OHA (song)
- Oakland Heritage Alliance
- Oakland Housing Authority
- Ofe Oha
- Office of Hawaiian Affairs
- Okha, Russia
- Oklahoma Hospital Association
- Omaha Housing Authority
- Ontario Hockey Association
- Ontario Horticultural Association
- Ontario Hospital Association
- Open Handset Alliance
- Oral Health America
- Oral History Association
- Oregon Health Authority
- Ormiston Horizon Academy
- Overseas housing allowance (United States military)
- RNZAF Base Ohakea
- Small Business Administration
- Ugo Oha
- Õha