| Acronym | Meaning |
| HO | Hand Off |
| HO | Hand-Over |
| HO | Handout |
| HO | Hands-On |
| HO | Headquarters Office |
| HO | Hearing Office (Social Security) |
| HO | Hearing Officer |
| HO | Height Obstacle |
| HO | Hinder Ordonnantie (Indonesian: Hinder Ordinance) |
| HO | History Office |
| HO | Hold Off |
| HO | Home Office |
| HO | Hospitalisation d'Office (French) |
| HO | Hostilities Only |
| HO | Humanitarian Operation |
| HO | Hydrographic Office |