| Acronym | Definition |
|---|
| ORT | Ornithobacterium Rhinotracheale (bacillus) |
| ORT | Oxford Reading Tree (UK) |
| ORT | Outbreak Response Team (various locations) |
| ORT | Opioid Replacement Therapy (medical procedure) |
| ORT | Oral Rehydration Therapy |
| ORT | Odor Recognition Test (National Association of Canine Scent Work) |
| ORT | Orchestra Regionale Toscana (Italian: Tuscany Regional Orchestra; Tuscany, Italy) |
| ORT | Open Road Tolling (electronic toll roadways) |
| ORT | Ongoing Reliability Testing |
| ORT | Out of Range Type |
| ORT | Old Republic Title (real estate title insurance) |
| ORT | Overall Response Time |
| ORT | Operation Restore Trust |
| ORT | Off-Road Technology (vehicles) |
| ORT | Ohana Reef Towers (Hawaii) |
| ORT | Operational Readiness Test |
| ORT | Ongoing Reliability Test(ing) |
| ORT | Organization for Educational Resources and Technological Training |
| ORT | Ozark Regional Transit (Arkansas) |
| ORT | Object Relations Technique |
| ORT | Object Recognition Test |
| ORT | Optical Relay Tube |
| ORT | Other Recurrent Transactions |
| ORT | Obschestvo Remeslenovo i Zemledelcheskovo Trouda (Russian: The Society for Trades and Agricultural Labour) |
| ORT | Orthodromic Reciprocating Tachycardia (cardiology) |
| ORT | Operational Readiness Training |
| ORT | Original Reference Tree (property) |
| ORT | Obshchestvennoe Rossiiskoe Televidenie (Russian Public Television) |
| ORT | Overland Radar Technology |
| ORT | Origin Rail Terminal |
| ORT | Operationally Ready Time |
| ORT | Over Roof-Top (electromagnetic wave propagation) |
| ORT | Operation Room Technician (medical) |
| ORT | Operational Reliability Test |
| ORT | Owners Requirement Table (AVIONICS) |
| ORT | Operational Requirements Tool |
| ORT | Operand Rename Table |
| ORT | Optimized Reverse-Tree |