| P&O | Peninsular and Oriental Steamship Company |
| P/O | Pilot Officer |
| pa | per annum (a year) |
| PAO | Prince Albert's Own |
| Parl(y) | Parliament(ary) |
| PASI | Professional Associate, Chartered Surveyors' Institution |
| PBMA | President of the British Medical Association |
| PC | Privy Council/Counsellor; Police Constable; Perpetual Curate; Peace Commissioner (Ireland); Progressive Conservative (Canada) |
| PCC | Parochial Church Council |
| PCFC | Polytechnics and Colleges Funding Council |
| Pde | Parade |
| PE | Procurement Executive |
| Pembs | Pembrokeshire |
| PEN | Poets, Playwrights, Editors, Essayists, Novelists (Club) |
| PEng | Registered Professional Engineer (Canada); Member, Society of Professional Engineers |
| Penn | Pennsylvania |
| PEP | Political and Economic Planning |
| Perm | Permanent |
| PF | Procurator-Fiscal |
| PGA | Professional Golfers' Association |
| PHAB | Physically Handicapped and Able-Bodied |
| PhD | Doctor of Philosophy |
| Phil | Philology, Philological; Philosophy, Philosophical |
| Phys | Physical |
| PIA | Personal Investment Authority |
| PITCOM | Parliamentary Information Technology Committee |
| Pk | Park |
| Pl | Place; Plural |
| PLA | Port of London Authority |
| Plen | Plenipotentiary |
| PLP | Parliamentary Labour Party; Progressive Liberal Party (Bahamas) |
| PLR | Public Lending Right |
| PM | Prime Minister |
| PMG | Postmaster-General |
| PMO | Principal Medical Officer |
| PMRAFNS | Princess Mary's Royal Air Force Nursing Service |
| Pncpl | Principal |
| PNEU | Parents' National Educational Union |
| PO | Post Office |
| Poly | Polytechnic |
| Pop | Population |
| POUNC | Post Office Users' National Council |
| POW | Prisoner of War; Prince of Wales's |
| pp | pages |
| PPA | Periodical Publishers Association |
| PPCLI | Princess Patricia's Canadian Light Infantry |
| PPE | Philosophy, Politics and Economics |
| PPS | Parliamentary Private Secretary |
| PQ | Province of Quebec |
| PR | Public Relations; Parti republicain |
| PRA | President, Royal Academy |
| PRAS | President, Royal Agricultural Society |
| PRBA | President, Royal Society of British Artists |
| PRCS | President, Royal College of Surgeons |
| PRE | President, Royal Society of Painter-Printmakers (formerly of Painter-Etchers and Engravers) |
| Preb | Prebendary |
| Pres | President |
| PRIA | President, Royal Irish Academy |
| Priv | Private |
| PRO | Public Relations Officer, Public Records Office |
| Prob. | Probate; Probation; Probationary |
| Proc | Proctor; Proceedings |
| Prof | Professor; Professional |
| Prov | Province; Provost, Provincial |
| PRS | President, Royal Society; Performing Right Society Lid |
| PRSM | President, Royal Society of Medicine |
| PRSW | President, Royal Scottish Water Colour Society |
| PRWA | President, Royal West of England Academy |
| PS | Pastel Society; Paddle Steamer |
| PSA | Property Services Agency; Petty Sessions Area |
| psc | Passed Staff College Camberley; Graduate of Staff College |
| PSD | Petty Sessional Division; Social Democratic Party (Portugal) |
| PSI | Policy Studies Institute |
| PTA | Passenger Transport Authority; Parent-Teacher Association |
| Pte | Private |
| ptnr | partner |
| Pty | Proprietary (used of Australian and some other countries' businesses) |
| Publicns | Publications |
| PWD | Public Works Department |
| PWE | Political Welfare Executive |
| PWO | Prince of Wales's Own |