| Acronym | Definition |
|---|
| PO | Post Office |
| PO | Purchase Order |
| PO | Petty Officer (military rank) |
| PO | Pissed Off |
| PO | Pouces (French: Inches) |
| PO | Piss Off |
| PO | Per Os (Latin: by mouth, orally) |
| PO | Parole Officer |
| PO | Pool |
| PO | Program Office(r) |
| PO | Put Out |
| PO | Pacific Ocean |
| PO | Project Officer |
| PO | Police Officer |
| PO | Portugal (Including Azores Island & Madeirais) |
| PO | Postal Order |
| PO | Phone Order (medical) |
| PO | Peak Oil |
| PO | Portsmouth (UK postal code) |
| PO | Port Orchard (Washington) |
| PO | Palm Oil |
| PO | Pull Off (guitar playing technique) |
| PO | Private Organization |
| PO | Purchasing Office |
| PO | Previous Owner |
| PO | Primary Objective |
| PO | Probation Officer |
| PO | Platforma Obywatelska (Citizens Platform, Poland) |
| PO | Production Order |
| PO | Partial Order |
| PO | Post-Operative |
| PO | Polonium |
| PO | Performance Objective |
| PO | Presiding Officer |
| PO | Propylene Oxide |
| PO | Partner Organization |
| PO | Por Orden (Spanish: on Behalf of and By Order Of) |
| PO | Peace Out |
| PO | Program Operations |
| PO | Partido Obrero (Argentina political party) |
| PO | Polikarpov (Soviet aircraft designer) |
| PO | Procurement Officer |
| PO | Pick Off |
| PO | Payment Order |
| PO | Personnel Officer |
| PO | Previous Orders |
| PO | Presidential Office |
| PO | Physical Optics |
| PO | peace operations (US DoD) |
| PO | Principal Only |
| PO | Pilot Officer (Royal Air Force) |
| PO | Prato, Toscana (Italian province) |
| PO | Point of Observation |
| PO | Process Owner |
| PO | Procurement Operations |
| PO | Project Order |
| PO | Parity Odd |
| PO | Planning Order |
| PO | Disney's Port Orleans Resort |
| PO | Postal Operator (PostEurop) |
| PO | Pump Operator (fire department) |
| PO | Planning Objective |
| PO | Personnel & Organization |
| PO | Patrologia Orientalis |
| PO | Packet Oriented |
| PO | Provocative Operation (Edward De Bono) |
| PO | Peace Opportunity |
| PO | Política Operativa (Italian: Operational Policy) |
| PO | Production Offset |
| PO | Preventive Officer |
| PO | Phosphorus Monoxide (chemistry) |
| PO | Possession of the US (IRB) |
| PO | Presiding Overseer |
| PO | Directie Primair Onderwijs (Dutch) |
| PO | Partial Overlaps (spatial reasoning) |
| PO | Probability of Outage |
| PO | Prenegotiation Objective (USACE) |
| PO | Sand/Dust Whirls (METAR weather) |
| PO | Petite Ondes (French: microwave) |
| PO | Partition Organized |
| PO | Poop Occurs :-) |
| PO | Propositioning Objective |
| PO | Program Originator Code |
| PO | Pilot-Only Receiver |
| PO | Program/Procurement Objective |
| PO | Prologue Overhead |
| PO | Perilmondo Onlus (Sri Lanka; est. 2004) |