NAIA is an acronym (or an initialism) that can refer to the following:
- National Association of Intercollegiate Athletics in the United States.
- Ninoy Aquino International Airport, in Pasay City and Parañaque City, Philippines, nearby Manila and inside Metro Manila
- National Animal Interest Alliance in the United States.
- Newfoundland Aquaculture Industry Association in Canada.
- North American Institute of Aviation in the United States.