| Acronym | Definition |
|---|
| HTO | Happy to Oblige |
| HTO | High Temperature Oxidation |
| HTO | High Tibial Osteotomy |
| HTO | Tritiated Water |
| HTO | Habitual Traffic Offender (driving; various locations) |
| HTO | Human, Technology and Organization |
| HTO | Hudson Trail Outfitters (various locations) |
| HTO | High-Tech Offensive (Bayern; software) |
| HTO | Halal Transactions of Omaha (Omaha, NE) |
| HTO | Hellenic Telecommunications Organisation SA (Greece) |
| HTO | Hostile Take Over |
| HTO | Hard to Operate (vehicle repair) |
| HTO | Horizontal Take-Off |
| HTO | Hydrogen Tritium Oxygen |
| HTO | Hospital Transfer Order |
| HTO | Highway Transportation Officer |