PSA
- Andalusian Party
- Argentine Socialist Party
- Authentic Socialist Party (Argentina)
- Autonomous Socialist Party (disambiguation)
- Bad Day (R.E.M. song)
- New Zealand Public Service Association
- PSA (song)
- PSA 5.7 Rock
- PSA Airlines
- PSA BPOL
- PSA Certified
- PSA Group
- PSA International
- Pacific Science Association
- Pacific Sociological Association
- Pacific Southwest Airlines
- Palestinian Scout Association
- Palmetto State Armory
- Parti Solidaire Africain
- Partnership for a Secure America
- Passenger Vessel Services Act of 1886
- Payment Services Act
- Penal substitution
- Penn Station Access
- People's Struggle Alliance
- Persistent staging area
- Petroleum Safety Authority
- Petroleum Safety Authority Norway
- Pharmaceutical Society of Australia
- Philippine Statistics Authority
- Philosophy of Science Association
- Phone-paid Services Authority
- Photographic Society of America
- Pi Sigma Alpha
- Pisa International Airport
- Pisa language
- Piscis Austrinus
- Plesk
- Poetry Society of America
- Polar surface area
- Polish Society of Actuaries
- Political Studies Association
- Posterior spinal artery
- Poultry Science Association
- Power Station of Art
- Pressure swing adsorption
- Pressure-sensitive adhesive
- Primary statistical area
- Primary systemic amyloidosis
- Pro Snowboarders Association
- Problem-solution approach
- Production sharing agreement
- Professional Skaters Association
- Professional Sports Authenticator
- Professional Squash Association
- Professional Standards Authority for Health and Social Care
- Professional services automation
- Property Services Agency
- Prostate-specific antigen
- Pseudomonas aeruginosa
- Pseudomonas syringae pv. actinidiae
- Psoriatic arthritis
- Public Safety Act
- Public Schools Association
- Public Servants Association of South Africa
- Public Service Association of NSW
- Public Services Association
- Public Storage
- Public service agreement
- Public service announcement
- Purchase and sale agreement
- Socialist Party of Aragon
- The Salvation Army, Parramatta