| OPO | ODOT Procurement Office 
| Others |
| OPO | Oeschger Paul in Oerlikon
| Others |
| OPO | Offensive Player Only
| Others |
| OPO | Office of Police Ombudsman
| Others |
| OPO | Office of Police Oversight
| Others |
| OPO | Office of Procurement Operations
| Others |
| OPO | Office of Program Operations
| Others |
| OPO | Office of the Police Ombudsman
| Others |
| OPO | Office Products Outlet
| Others |
| OPO | Offshore Passage Opportunities
| Others |
| OPO | Old Post Office
| Others |
| OPO | On Page Optimization
| Others |
| OPO | One Person Operation
| Others |
| OPO | One Plus One
| Others |
| OPO | Online Public Offering
| Others |
| OPO | Operational Performance Objective
| Others |
| OPO | Ophthalmic and Physiological Optics
| Others |
| OPO | Ophthalmic Physiol Opt
| Others |
| OPO | Optical Parametric Oscillator
| Others |
| OPO | Optical parametric oscillators
| Others |
| OPO | Oracle Power Objects
| Others |
| OPO | Oral Performance Option
| Others |
| OPO | Oral Protection Only
| Others |
| OPO | Orbiter Projects Office
| Others |
| OPO | Orchestrated Power Outlet
| Others |
| OPO | Order Pizza for Operator
| Others |
| OPO | Organ Procurement Organization
| Others |
| OPO | Organ procurement organizations
| Others |
| OPO | Organization of Phenomenological Organizations
| Others |
| OPO | Outdoor Programs Office
| Others |
| OPO | Ovamboland People's Organization
| Others |
| OPO | Overdose Prevention Ottawa
| Others |
| OPO | Owen, Patterson, & Owen
| Others |
| OPO | Oxbridge Parent Organization
| Others |
| OPO | Porto, Portugal
| Others |