Businesses
- P Bourke and Company
- P Brennan and Company
- P Brooke Kelly, dispensing and retail chemist
- P Lloyd Rees Limited
- P McEvoy Sons and Pinnington Limited
- Palgrave, Murphy and Company, steam ship owners and agents
- Palmer and Elliot
- Pannett and Neden
- Parkgate Street Crown Forces' Home
- Patrick Reddy, fish and fowl dealer
- Paul Brothers, flour merchants
- Paving Committee
- Peamount Sanatorium
- Pembroke Urban District Council
- Perfect Dairy Machines Limited
- Perrier Limited
- Petrie Brothers
- Petty and Sons (Leeds) Limited
- Pickering and Company
- Pickfords Limited, general carriers
- Picture House
- Pigott and Company Limited
- Pilchers Limited
- Pillar Café
- Pillar House, jewellers
- Pim Brothers Limited
- Pioneer Teeth Institute Limited
- Portmarnock Golf Club
- Post Office (Ireland) Convalescent Homes and Sanatoria Fund
- Poultry, Fish and Fruit Supply Company
- Powells, press printers
- Premier Whist Club
- Presbyterian Church
- Prescott's Dye Works
- Presentation Convent, Cork
- Price's Patent Candle Company Limited
- Prince's Stores
- Prinzen Van Glabbeck Limited
- Proprietors of the Irish Rosary
- Provident Association of London Limited
- Provident Clerks and General Guarantee and Accident Company
- Provident Clothing and Supply Company Limited
- Provincial Bank of Ireland Limited
- Provincial Hotel
- Public Record Office of Ireland
- Purveyors and Family Grocers' Assistants Association