Name
- O'Shanly, J-, Lieutenant1
- Ogilvie, William, Surgeon1
- Ompteda, Dietrich Heinrich Ludwig von?, Hanoverian minister at the Diet of the Empire1
- Orsini, Vincenz Ferrerius Andreas, Count Rosenberg1
- Osborn, George, 4th Baronet1
- Paar, Johann Wenzel, Prince1
- Parker and Wakelin, Messrs1
- Parker, Charles, of Add MS 355321
- Patin, Vicomtesse -, née Leighton1
- Pergen, Christianne1
- Peter III, of Russia1
- Petty, Diana Amelia1
- Petty, John Henry, Earl of Wycombe, and (1805) 2nd Marquis of Lansdowne1
- Phillips, W-, Colonel1
- Pierrepont, Elizabeth, widow of Evelyn, 2nd Duke of Kingston1
- Pitt, Thomas, of Add MS 355321
- Pitt, William Morton, FRS, MP for Dorsetshire1
- Pius VI, Pope1
- Plunkett, Arthur James, 7th Earl of Fingall1
- Plunkett, Arthur James, 8th Earl of Fingall1