| Acronym | Definition |
|---|
| FSU | Florida State University |
| FSU | Ferris State University |
| FSU | Fayetteville State University (North Carolina) |
| FSU | Former Soviet Union |
| FSU | Frostburg State University |
| FSU | Fitchburg State University (Massachusetts) |
| FSU | Fairmont State University (Fairmont, WV) |
| FSU | Finance Sector Union |
| FSU | Fédération Syndicale Unitaire (French trade union) |
| FSU | Fast Software Upgrade |
| FSU | Floating Subtraction |
| FSU | Fiber Service Unit |
| FSU | Fast Service Upgrade |
| FSU | Financial Services Union (Australia) |
| FSU | Floating Storage Unit |
| FSU | Fresno State University |
| FSU | Friends Stand United (gaming clan) |
| FSU | Functional Spinal Unit (orthopedic testing) |
| FSU | Fast Software Upgrade (Cisco) |
| FSU | Food Safety Unit (various locations) |
| FSU | Friends Stand United (Boston) |
| FSU | Family Service Unit |
| FSU | Free Standing Unit |
| FSU | Fuel Sending Unit (automotive) |
| FSU | Field Services Unit |
| FSU | Ferry Service Unit (US Navy) |
| FSU | Friedrich Schiller Universität of Jena (German: Friedrich Schiller University of Jena) |
| FSU | Freeze Substitution Unit |
| FSU | Feminist Students United |
| FSU | Forward Support Unit |
| FSU | Fanshawe Student Union (Fanshawe College, London, Ontario, Canada) |
| FSU | Finance Support Unit |
| FSU | Field Storage Unit (ammunition) |
| FSU | Flat Side Up (fluid mechanics) |
| FSU | File Swapping Utility |
| FSU | Frequency Synthesizer Unit |
| FSU | Frame Synchronization Unit |
| FSU | Former Spousal Unit |
| FSU | Fantasy Sports Unlimited |
| FSU | Friends Should Unite |
| FSU | Functional Support Unit |
| FSU | Flight Status Update |
| FSU | Foul Stuff Up (polite form) |
| FSU | Fast-Spike Unit (neurobiology) |