| Abbreviation | Definition |
|---|---|
| OPG | Orbital Police Guard |
| OPJ | Officier de police judiciaire |
| OPJ | Officiers De Police Judiciaire |
| OPL | Over Prescribed Limit |
| OPN | Orcutt Police Nunchaku |
| OPO | Office of Police Oversight |
| OPO | Office of the Police Ombudsman |
| OPP | Ontario Prov Police |
| OPP | Ontario Provincial Police |
| OPPN | Opposition |
| OPSE | Office of Police Secondary Employment |
| OPSG | OPeration Stone Garden |
| OPSO | Ouachita Parish Sheriff's Office |
| OPSR | Office of Public Services Reform |
| ORDP | Officer Recuitment Diversity Program |
| ORS | Oregon Revised Statutes |
| ORWD | Off-Reservation Work Detail |
| OSAF | Odisha Special Action Force |
| OSC | Office of the Surveillance Commissioners |
| OSCE | Organisation for Security and Co-operation in Europe |