| U&P | Username and Password 
| Others |
| UP | Un Planned
| Others |
| UP | Unified Process
| Others |
| UP | Union Pacific
| Others |
| UP | Union Pacific Railroad
| Others |
| UP | Union-Pearson
| Others |
| UP | Unit Price
| Others |
| UP | United Party
| Others |
| UP | United Press
| Others |
| UP | Universidad del Pacífico
| Others |
| UP | Universidad Popular
| Others |
| UP | Universidade do Porto
| Others |
| UP | Universiteit van Pretoria (University of Pretoria)
| Others |
| UP | University of Pennsylvania
| Others |
| UP | University of Peshawar
| Others |
| UP | University of Portland
| Others |
| UP | University of Pretoria
| Others |
| UP | University of the Philippines
| Others |
| UP | University Place
| Others |
| UP | University Press
| Others |
| UP | Unknown Precipitation
| Others |
| UP | Unlimited Parking
| Others |
| UP | Unlimited Power
| Others |
| UP | Unrotated Projectile
| Others |
| UP | Unsolicited Proposal
| Others |
| UP | Unstoppable Prosperity
| Others |
| UP | Unwired Planet
| Others |
| UP | Uplifting Entertainment
| Others |
| UP | Upper Peninsula
| Others |
| UP | Urban Planner
| Others |
| UP | UreteraPelvic
| Others |
| UP | Urticaria Pigmentosa
| Others |
| UP | Usb Printer
| Others |
| UP | Used Part
| Others |
| UP | User Profile
| Others |
| UP | Usine De Plutonium
| Others |
| UP | Utilizing Potential
| Others |
| UP | Uttar Pradesh
| State |
| UP! | it means to go well... up like in the sky *points up*
| Others |