PSU
- Fairchild F8
- Pacific States University
- Palawan State University
- Pangasinan State University
- Papua State University
- Parti Socialiste Unifié (disambiguation)
- Partido State University
- Passenger service unit
- Pembroke State University
- Pennsylvania State University
- Personal Support Unit
- Phantasy Star Universe
- Pittsburg State University
- Plattsburgh State University
- Plymouth State University
- Police Support Unit
- Police support unit (United Kingdom)
- Polysulfone
- Port Security Unit
- Portland State University
- Power supply unit (computer)
- Practical salinity unit
- Prince Sultan University
- Prince of Songkla University
- Projective special unitary group
- Prudential Staff Union
- Prueba de Selección Universitaria
- Public sector undertakings in India
- Puntland State University
- United Socialist Party (Bolivia)