UOP
- Honeywell UOP
- Micro-operation
- Tripoli, Greece
- Ukroboronprom
- University of Ottawa Press
- University of Patras
- University of Peloponnese
- University of Pennsylvania
- University of Peradeniya
- University of Peshawar
- University of Petra
- University of Phoenix
- University of Plymouth
- University of Portsmouth
- University of Pretoria
- University of Pune
- University of the Pacific (Peru)
- University of the Pacific (United States)
- Uranus Orbiter and Probe
- Urząd Ochrony Państwa
- User operation prohibition