Name
- Merveldt, Maximilian, General Count; afterwards Austrian Ambassador in London1
- Mesemacre de Lardenois-de-Ville, Joseph, Baron1
- Milbanke, John Ralph, 8th Baronet 18501
- Mont, -, army officer and correspondent of Sir Frederick James Lamb, fl 18131
- Morier, David Richard, diplomat, 1784-18771
- Murdoch, John, RC Bishop of Castabala; Vicar-Apostolic1
- Mure, William, MP; classical scholar1
- Murphy, Miletius, RC Bishop of Ferns1
- Murphy, Timothy, RC Bishop of Cloyne1
- Münster, Ernst Friedrich Herbert zu, Count Hanoverian Minister in London1
- Navy of England1
- Navy of France1
- Neipperg, Adam Albert, Count, Austrian general1
- Nesselrode, Charles Robert, Count, Russian statesman1
- O'Donnell, Lewis, RC Bishop of Galway1
- Oettingen-Wallerstein, Ludwig Kraft Ernst, Prince, Bavarian statesman; of Add MS 431411
- Ordnance Office1
- Parliament1
- Piscatory, Théobald Émile Arcambal, French Minister in Athens1
- Pius VII, Pope1