| Surname | Forename | Rank | Unit | Born | Resided |
| PIKE | Samuel | Petty Officer 2nd Class | H.M.S. "Victory" | | |
| PILE | Cyril John | Second Lieutenant | 12th Squadron, Royal Flying Corps and Royal Field Artillery | Born Dublin | |
| PIM | Francis Joseph | Acting Sergeant | Corps of Military Police | Born Dublin | Resided Rusholme |
| PINFIELD | Guy Vickery | Second Lieutenant | 8th (King's Royal Irish) Hussars | | |
| PLANT | J. B. L. | Second Lieutenant | Royal Dublin Fusiliers, attached 17th Battalion, Royal Fusiliers | Born at Boyle, Co. Roscommon | |
| PLEASANT | George | Sergeant | Sherwood Foresters (Nottinghamshire and Derbyshire Regiment) | Born Dublin | |
| PLOWMAN | J | Captain | 2nd Battalion, Leinster Regiment | | |
| PLUNKETT | Gerald | Sub-Lieutenant | Collingwood Battalion, Royal Navy Division | | |
| PLUNKETT | Bartle | Private | Royal Dublin Fusiliers | Born Clonsilla, Co. Dublin | |
| POE | Charley Vernon Leslie | Captain | 4th Battalion, King's Royal Rifle Corps | | |
| POLLARD | Daniel | Private | Connaught Rangers | Born Dublin | Resided Dublin |
| POLLOCK | Hugh Crawford | Private | Royal Dublin Fusiliers | Born Dublin | Resided Dublin |
| POMEROY | Eustace Crichton | Private | Royal Army Service Corps | Born Dublin | Resided Mount Charles, Co. Donegal |
| POPE | Edward | Private | Irish Guards | Born Dublin | |
| PORTER | William Ridgeway | Lieutenant | 18th Battalion Australian Infantry, Australian Imperial Force | Born at Dublin | |
| PORTER | George Francis Lambert | Captain | A Company, 11th Battalion, West Yorkshire Regiment (Prince of Wales's Own) | | |
| PORTER | Matthew | Private | Royal Dublin Fusiliers | Born Dublin | |
| PORTER | Robert Cyril | Private | Royal Dublin Fusiliers | Born Clontarf, Dublin | |
| PORTER | William | Private | Royal Munster Fusiliers | Born St. Lawrence O'Toole, Dublin | |
| POTTER | Charles | Private | Royal Dublin Fusiliers | Born Dublin | |
| POTTERTON | William Hubert | Lieutenant | Corps of Royal Engineers | Born at Dublin | |
| POULTER | Henry Chapman | Captain | 8th Battalion, Royal Dublin Fusiliers | | |
| POULTER | Wilfred Forman | Second Lieutenant | 24th Squadron, Royal Flying Corps | | |
| POULTON | Joseph Arthur | Private | Household Cavalry and Cavalry of the Line (including Yeomanry) | Born St. George's, Dublin | |
| POWELL | Frederick William | Second Lieutenant | 5th Battalion, attached 10th Battalion, Royal Dublin Fusiliers | Native of Dublin | |
| POWELL | Benjamin | Private | Royal Irish Regiment | Born St. Lawrence O'Toole, Dublin | |
| POWELL | Francis David | Gunner | Royal Garrison Artillery | Born Dublin | Resided Bootle, Lancs |
| POWELL | James Ernest | Lance Corporal | Connaught Rangers | Born Dublin | Resided Forest Gate |
| POWELL | William | Private | Royal Dublin Fusiliers | Born Dublin | |
| POWER | Henry Horace | Private | 16th Battalion, Australian Infantry, Australian Imperial Force | Born at Cork | |
| POWER | George | Private | Connaught Rangers | Born Dublin | Resided Dublin |
| POWER | James | Private | Royal Irish Regiment | Born St. James, Dublin | Resided Ballyduff, Co. Waterford |
| POWER | John | Private | Royal Dublin Fusiliers | Born Dublin | Resided Clare Castle, Co. Clare |
| POWER | John | Private | King's (Liverpool Regiment) | Born Dublin | Resided Liverpool |
| POWER | John | Corporal | Cameronians (Scottish Rifles) | Born St. Andrew's, Dublin | |
| POWER | Patrick | Private | Connaught Rangers | Born Dublin | Resided Galway |
| POWER | Samuel | Corporal | Royal Dublin Fusiliers | Born Dublin | |
| POWER | Thomas | Corporal | Royal Garrison Artillery | Born Dublin | Resided Plumstead, Kent |
| POWER | William | Private | Prince of Wales's Leinster Regiment (Royal Canadians) | Born Dublin | |
| PRATT | William John Armstrong | Captain | 3rd Battalion, attached 1st Battalion, The King's (Liverpool Regiment) | | |
| PRATT | Joseph Benjamin | Private | Household Cavalry and Cavalry of the Line (including Yeomanry) | Born Dublin | Resided Chelmsford, Essex |
| PRENDERGAST | John | Lance Corporal | Northumberland Fusiliers | Born Dublin | |
| PRENDERGAST | William | Private | Royal Dublin Fusiliers | Born Dublin | |
| PRENTICE | Walter Lowry | Second Lieutenant | 4th Battalion, Connaught Rangers | | |
| PRESCOTT | George Crooke | Corporal | Corps Of Royal Engineers | Born Dublin | Resided Edinburgh |
| PRESTAGE | Ralph | Sergeant | Royal Dublin Fusiliers | Born Dublin | |
| PRESTON | Richard | Private | Royal Inniskilling Fusiliers | Born Dublin | |
| PRICE | Charles | Able Seaman | S.S. "Artist" (Liverpool) | Born in Dublin | |
| PRICE | Guy William | Flight Commodore | 8th (Naval) Squadron | | |
| PRICE | Francis | Sapper | Corps Of Royal Engineers | Born Dublin | |