IPA
- .ipa
- 3-Indolepropionic acid
- FreeIPA
- Important Plant Areas
- Independence Party of America
- Independent Paralympians at the Paralympic Games
- Independent Pilots Association
- Independent Psychiatric Association of Russia
- Independent practice association
- India pale ale
- Indian Pharmacist Association
- Indian Polo Association
- Indigenous Protected Area
- Infrastructure and Projects Authority
- Innovations for Poverty Action
- Innovative Products of America
- Insolvency Practitioners Association
- Institute for Propaganda Analysis
- Institute of Practitioners in Advertising
- Institute of Public Accountants
- Institute of Public Administration (disambiguation)
- Institute of Public Affairs
- Institute of Public Affairs, Poland
- Instituto Superior Autónomo de Estudos Politécnicos
- Instituto de Profesores Artigas
- Instrument for Pre-Accession Assistance
- Interaction process analysis
- Intermediate power amplifier
- International Peoples' Assembly
- International Permafrost Association
- International Phonetic Alphabet
- International Phonetic Association
- International Play Association
- International Police Association
- International Polka Association
- International Psychoanalytical Association
- International Publishers Association
- Interpretative phenomenological analysis
- Investigatory Powers Act 2016
- Involvement and Participation Association
- Ipa (spider)
- Island Pacific Academy
- Isopropyl alcohol
- Presentation Sisters