Name
- O'Loghlen, Michael, 1st Baronet Irish Solicitor-General1
- O'Neill, John Thomas1
- O'Neill, Terence, Captain; RN1
- Orme, Robert, East India Company official and historian, 1728-18011
- Ormsby, C-, Reverend1
- Osborne, Louisa Catharine, widow Sir F B Hervey and wife of Francis, Marquis of Carmarthem1
- Ossorio, Vicinte, Colonel1
- Ouseley, Harriet Georgina, wife of Sir Gore Ouseley 1st Baronet1
- Ouseley, William, orientalist, 1767-18421
- Ouvaroff, Sergius Semenovitch, Count1
- Owen, Edward William Campbell Rich, Admiral1
- Oxxenni, Federico, Baron1
- Pakenham, Thomas, 2nd Earl of Longford1
- Palafox1
- Palmer, William, of Add MS 372791
- Parker, John, 1st Earl of Morley, politician, 1772-1840, http://isni.org/isni/000000... http://viaf.org/viaf/560352111
- Parsons, Laurence, 2nd Earl of Rosse1
- Pasley, Charles, East India Company officer, fl 1797-18211
- Pasqual y Rico, Juan1
- Patnee Mull, Rajah of Benares?1