OHA

The acronym OHA may refer to:
 * On hand Always
 * DHS Office of Health Affairs, an office in the United States Department of Homeland Security
 * Oakland Heritage Alliance, a non-profit preservation organization in Oakland, California.
 * Oakland Housing Authority
 * Office of Hawaiian Affairs
 * Office of Hearings and Appeals, within the US Small Business Administration
 * Office of Human Affairs, a Community Action Agency serving the residents of Newport News and Hampton, Virginia.
 * Oklahoma Hospital Association, the state affiliate of the American Hospital Association
 * Omaha Housing Authority, the government agency responsible for providing public housing in Omaha, Nebraska, USA
 * Ontario Hockey Association, which governs most junior and senior hockey in Ontario
 * Ontario Horticultural Association
 * Ontario Hospital Association
 * Open Handset Alliance, a consortium of companies dedicated to producing an open standard for mobile devices.
 * Oral hypoglycemic agents, the majority of anti-diabetic drugs
 * Oral Health America
 * Oregon Health Authority
 * Ormiston Horizon Academy
 * Oral History Association, a professional association for oral historians
 * Overseas housing allowance (United States military)
 * RNZAF Base Ohakea, New Zealand, which uses IATA code OHA

Oha may refer to:
 * Õha, village in Kaarma Parish, Saare County, Estonia
 * Ugo Oha, a Nigerian basketball player
 * Ofe Oha, a Nigerian soup