| FAT | File Allocation Table | |
| FAT | Fatalities | |
| FAT | Fabulous and Thick | |
|
| FAT | Faithful and True | |
| FAT | Fresh Air Time | |
| FAT | Financial Aid Transcript | |
| FAT | Famine and Temperature (weight loss program) | |
| FAT | Factory Acceptance Test | |
| FAT | Forest and Trees | |
| FAT | Freude am Tanzen (German band) | |
| FAT | Forces Armees Togolaises (French: Togolese Armed Forces) | |
| FAT | Faculty of Advanced Technology (University of Glamorgan; UK) | |
| FAT | Floating-Arm Trebuchet | |
|
| FAT | Fashion Art Toronto (Toronto, Ontario, Canada) | |
| FAT | Focal Atrial Tachycardia | |
| FAT | Formative Assessment Task | |
| FAT | Fully Automatic Timing (track and field competition) | |
| FAT | First Atlanta Tower | |
| FAT | Fashion Architecture Taste (architecture/interior design firm; London, UK) | |
| FAT | Fonds des Accidents du Travail (French) | |
| FAT | First Article Test | |
| FAT | Fluorescent Antibody Test | |
| FAT | Faithful Available and Teachable | |
| FAT | Fatty Acid Transferase | |
| FAT | Frequently Asked Topics | |
| FAT | File Access Table (common but incorrect) | |
| FAT | First Article Testing | |
| FAT | Faithful and Teachable (religious slang) | |
| FAT | Facility Acceptance Test | |
| FAT | Final Acceptance Test | |
| FAT | Field Acceptance Test | |
| FAT | Foreign Area Translation | |
| FAT | Festival d'Automne de Toulouse (French: Toulouse Autumn Festival) | |
| FAT | Fédération Autonome des Transports (French: Autonomous Federation of Transport) | |
| FAT | Final Acceptance Trial | |
| FAT | Fédération d'Aïkido Traditionnel (French: Federation of Traditional Aikido; martial arts) | |
| FAT | Fresno, CA, USA - Fresno Air Terminal (Airport Code) | |
| FAT | Forward Application Transport | |
| FAT | Flow Allocation Table | |
| FAT | Functional Acceptance Test(ing) | |
| FAT | Fugitive Apprehension Team (law enforcement) | |
| FAT | Flexible, Adaptable and Teachable | |
| FAT | Football Association of Tanzania (now Tanzania Football Federation) | |
| FAT | Federate Acceptance Test | |
| FAT | Flores Adventure Tours | |
| FAT | Free Air Temperature | |
| FAT | Florida Alfa Tango (dance group) | |
| FAT | Flight Aptitude Test (aviation; UK) | |
| FAT | Fabrication, Assembly and Test | |
| FAT | Flight Acceptance Test | |
| FAT | Fixed Assets Tracking (software) | |
| FAT | Functional Area Team | |
| FAT | Funding Allowance Target (US Property and Fiscal Office) | |
| FAT | Fool At Terminal | |
| FAT | Facilities Acquisition Team | |
| FAT | Family Acknowledgement Tree | |