| Acronym | Meaning |
| ALERT | Acute Launch Emergency Reliability Tip (NASA) |
| ALERT | Acute Launch Emergency Restraint Tip |
| ALERT | Advanced Linked Extended Reconnaissance and Targeting |
| ALERT | Advanced Local Emergency Response Team (anti-terrorist unit; North Carolina) |
| ALERT | Advanced Logistics Evaluation and Reporting |
| ALERT | Air Logistics Early Requirements Test |
| ALERT | Air-Land Enhanced Reconnaissance and Targeting |
| ALERT | Aircraft Low Energy Retrieval Technique (USAF) |
| ALERT | America's Law Enforcement Retiree Team |
| ALERT | Arctic Long-term Environmental Research Transects Program (US EPA) |
| ALERT | Attack and Launch Early Reporting to Theater |
| ALERT | Automated Law Enforcement Response Team |