| OTAN | Outreach and Technical Assistance Network | 外联和技术援助网络 |
| OTAN | Organização do Tratado do Atlântico Norte (Portuguese: North Atlantic Treaty Organization) | Organização do Tratado do Atlântico Norte (Portuguese: North Atlantic Treaty Organization) |
| OTAN | Organisation du TraitÉ de l'Atlantique Nord (French: North Atlantic Treaty Organization) | Organisation du TraitÉ de l'Atlantique Nord (French: North Atlantic Treaty Organization) |
| OTAN | OrganizaciÓn del Tratado del AtlÁntico Norte (Spanish: North Atlantic Treaty Organization) | OrganizaciÓn del Tratado del AtlÁntico Norte (Spanish: North Atlantic Treaty Organization) |
| OTAN | Organisation du TraitÉ de l'Atlantique Nord | Organisation du TraitÉ de l'Atlantique Nord |
| OTAN | Organization of Tropical American Nematologists | 热带美洲线虫学家组织 |
| OTAN | Organização do Tratado do Atlântico Norte | Organização do Tratado do Atlântico Norte |
| OTAN | OrganizaciÓn del Tratado de AtlÁntico Norte | OrganizaciÓn del Tratado de AtlÁntico Norte |