Oia

Oia or OIA may refer to:

Places

 * Oia, Spain, a municipality in Galicia, in the province of Pontevedra
 * Oia, Greece, a small town on the island of Santorini
 * Oia, alternate name of Oea (Attica), a town of ancient Attica
 * Oia, alternate name of Oea (Thera), a town of ancient Thera (Santorini)

Transportation

 * Ourilândia do Norte Airport, an airport with IATA identifier OIA
 * Orlando International Airport ("OIA" is a local abbreviation), which actually uses the letters MCO for its airport designation

Government

 * Office of the Independent Adjudicator, the higher-education ombudsman in the United Kingdom
 * Official Information Act 1982, a piece of New Zealand legislation
 * Office of Insular Affairs, an office of the United States Department of the Interior
 * DHS Office of Intelligence and Analysis, an office of the United States Department of Homeland Security
 * Office of Intelligence and Analysis (Treasury Department), the intelligence organization of the U.S. Department of the Treasury
 * Oman Investment Authority, a sovereign wealth fund

Other uses

 * Oia (spider), a genus of spiders in the family Linyphiidae
 * Oahu Interscholastic Association, an athletic association of public secondary schools on the island of Oahu, Hawaii
 * Old Indo-Aryan, the earlier Indo-Aryan languages