| S/U | Set Up 
| Others |
| S/U | Slide Up
| Others |
| SU | Sage
| Others |
| SU | Sale Used
| Others |
| SU | Salisbury University
| Others |
| SU | Salt Lake City Field Office
| Others |
| SU | Samokhodnaya Ustanovka
| Others |
| SU | Sample Uniques
| Others |
| SU | Sampson University
| Others |
| SU | Scan Udp
| Others |
| SU | Scout Unit
| Others |
| SU | Scripture Union
| Others |
| SU | Sea Urchin
| Others |
| SU | Search Unit
| Others |
| SU | Secretory Unit
| Others |
| SU | Seismic Unix
| Others |
| SU | Sellout University
| Others |
| SU | Sensitivity Unit
| Others |
| SU | Service Unit
| Others |
| SU | Service Unlimited
| Others |
| SU | Set User
| Others |
| SU | Shield Upgrade
| Others |
| SU | Shut Up
| Others |
| SU | Shut Up!
| Others |
| SU | Side Upper
| Others |
| SU | Signal Unit
| Others |
| SU | Simultaneous Users
| Others |
| SU | Sindicato Unitario
| Others |
| SU | Single Unit
| Others |
| SU | Single User
| Others |
| SU | Skinners Union
| Others |
| SU | Sofia University
| Others |
| SU | Software Update
| Others |
| SU | Solar Urticaria
| Others |
| SU | Sonic Underground
| Others |
| SU | Sorceress University
| Others |
| SU | Soviet Union
| Others |
| SU | Soviet Union (former USSR, now Russia)
| Others |
| SU | Speak Up
| Others |
| SU | Special Unitary
| Others |
| SU | Specified User
| Others |
| SU | Speed Up
| Others |
| SU | Sperm Urinal
| Others |
| SU | Sport Utility
| Others |
| SU | Stack Up
| Others |
| SU | Stand Up
| Others |
| SU | Standard Units
| Others |
| SU | Stanford University
| Others |
| SU | State University
| Others |
| SU | Statistical Unit
| Others |
| SU | Straight Up
| Others |
| SU | Strategy Unit
| Others |
| SU | Stroke Unit
| Others |
| SU | Students Union
| Others |
| SU | Stumble Upon
| Others |
| SU | Sub-Unit
| Others |
| SU | Subresolution Un-attenuated
| Others |
| SU | Substance Use
| Others |
| SU | Substitue User
| Others |
| SU | Substitute User
| Others |
| SU | sulphonylurea
| Others |
| SU | Sum of Units
| Others |
| SU | Sundanese
| Others |
| SU | Sunday
| Others |
| SU | Super User
| Others |
| SU | Superultramodern Unification
| Others |
| SU | Supplemented Unit
| Others |
| SU | Support Unit
| Others |
| SU | SUppressor
| Others |
| SU | Swim up
| Others |
| SU | Swipe Up
| Others |
| SU | Switch User
| Others |
| SU | Switch Users
| Others |
| SU | Syntax Unit
| Others |
| SU | System User
| Others |
| SU | System Userper
| Others |