PAA
- Intravenous ascorbic acid
- Paa (disambiguation)
- Pacific American Airlines
- Pamoja African Alliance
- Pan African Association
- Pan American Association of Anatomy
- Pan American World Airways
- PanAfrican Archaeological Association
- Patriot Alliance Association
- Penny Arcade Adventures
- Peroxyacetic acid
- Perpetuities and Accumulations Act 1964
- Perpetuities and Accumulations Act 2009
- Personal alarm
- Phenylacetic acid
- Phosphoamino acid analysis
- Pickleball in Australia
- Pickleball in Australia
- Piezo Audio Amplifier
- Polish American Association
- Polyacrylamide
- Polyacrylic acid
- Population Association of America
- Portland Adventist Academy
- Primary Aromatic Amine
- Protect America Act of 2007
- Proto-Afroasiatic language
- Proto-Austroasiatic language
- Prueba de Aptitud Académica