Oia
- DHS Office of Intelligence and Analysis
- Linyphiidae
- Oahu Interscholastic Association
- Oea (Attica)
- Oea (Thera)
- Office of Insular Affairs
- Office of Intelligence and Analysis (Treasury Department)
- Office of the Independent Adjudicator
- Official Information Act 1982
- Oia (spider)
- Oia, Greece
- Oia, Spain
- Old Indo-Aryan
- Oman Investment Authority
- Orlando International Airport
- Ourilândia do Norte Airport
- Oya (disambiguation)