| Acronym | Definition |
|---|
| ONT | Ontario (old acronym - ON is now frequently used) |
| ONT | Optical Network Terminal |
| ONT | Optimizing Converged Cisco Networks (cisco CCNP exam) |
| ONT | On2 Technologies |
| ONT | Optimizing Networks |
| ONT | Optical Network Tester |
| ONT | Optical Network Termination |
| ONT | Ontario Northland Railway (government of Ontario; reporting car marks) |
| ONT | Ontario, CA, USA - Ontario International (Airport Code) |
| ONT | Our New Thread (Coats & Clark trademark on sewing thread) |
| ONT | Orchid Society of Northern Transvaal (South Africa) |
| ONT | Office of Naval Technology |
| ONT | Out of National Territory |
| ONT | Operational Noise Temperature |