| Acronym | Definition |
|---|
| SSU | Small Subunit |
| SSU | Sonoma State University |
| SSU | Savannah State University (Savannah, Georgia) |
| SSU | Shawnee State University (Ohio) |
| SSU | Superior State University (Michigan) |
| SSU | Salem State University (Massachusetts) |
| SSU | Sacramento State University |
| SSU | Security Service of Ukraine |
| SSU | Sunny-Side Up |
| SSU | Sunny Side Up |
| SSU | Salisbury State University |
| SSU | Southampton Solent University (UK) |
| SSU | Synchronization Supply Unit (Nortel) |
| SSU | Sveriges Socialdemokratiska Ungdomsförbund |
| SSU | System Start up |
| SSU | Select Size Unit |
| SSU | Start Stop Unit |
| SSU | Super Sport Utility |
| SSU | System Setup Utility |
| SSU | Special Services Unit |
| SSU | Strategic Services Unit (US DoD) |
| SSU | System Software Update |
| SSU | Süleyman Sah University (Istanbul, Turkey) |
| SSU | Sequential Shunt Unit |
| SSU | Shared Services Unit |
| SSU | Session Support Utility |
| SSU | Stratospheric Sounding Unit |
| SSU | Satellite Student Union (California) |
| SSU | Syktyvkar State University (Russia, Komi) |
| SSU | Saybolt Seconds, Universal (viscosity) |
| SSU | Ship Support Unit (US Navy) |
| SSU | Secondary Sampling Unit |
| SSU | Staff Support Unit |
| SSU | Sabbath School University (Michigan) |
| SSU | Adele H. Stamp Student Union (building code; University of Maryland) |
| SSU | Synchronisation Supply Unit (ITU) |
| SSU | Squadron Service Unit (US DoD) |
| SSU | Subsequent Signal Unit |
| SSU | Sight Survey Unit (target/sighting, military helicopter) |
| SSU | Single Subscriber Unit |
| SSU | System Synchronization Unit (Newbridge) |
| SSU | System Supervisory Unit |
| SSU | Sub-Sectoral Units |
| SSU | Supply and Service Union (Canada) |
| SSU | Services & Support Unit |
| SSU | System Services and Utilities |
| SSU | Surface Screen Unit |
| SSU | Surface Sensitivity Unit |
| SSU | Société Suisse d'Urologie (French: Swiss Society of Urology; Switzerland; est. 1994) |
| SSU | Super Scoop Up (Pokemon) |
| SSU | Shift Start-Up (various organizations) |
| SSU | Subsea and Umbilicals (energy exploration) |
| SSU | State Sites Unit (Illinois Environmental Protection Agency) |
| SSU | Software Size Unit |