Uia is a locality in the Marquesas Islands.

UIA can refer to:

• Argentine Industrial Union (Unión Industrial Argentina)
• International Islamic University Malaysia (Universiti Islam Antarabangsa)
• International Union of Architects (Union internationale des Architectes)
• Microsoft UI Automation, a computer accessibility technology
• Uganda Investment Authority
• UIA Mutual, an insurance company in the United Kingdom
• Ukraine International Airlines
• Ukrainian Insurgent Army
• Unemployment Insurance Agency, the agency that oversees unemployment compensation in the U.S. state of Michigan
• Union Internationale des Avocats (International Association of Lawyers)
• Union of International Associations
• United International Airlines, a Serbian cargo airline
• United Iraqi Alliance
• United Israel Appeal
• Universidad Iberoamericana in Mexico
• University of Agder (Universitetet i Agder)
• University of Antwerp (Universitaire Instelling Antwerpen)