Letter listing for 1800–1809
- Jacques Henri Bernardin de Saint-Pierre to Marguerite Charlotte Désirée de Saint-Pierre [née de Pelleporc], 1800–1813
- Jacques Henri Bernardin de Saint-Pierre to [unknown], after 1800
- Jacques Henri Bernardin de Saint-Pierre to [unknown], after 1800
- Jacques Henri Bernardin de Saint-Pierre to [unknown], 1800–1814
- Jacques Henri Bernardin de Saint-Pierre to [unknown], 1800–1801
- Jacques Henri Bernardin de Saint-Pierre to [unknown], 1800–1804
- Jacques Henri Bernardin de Saint-Pierre to Lucien Bonaparte, principe di Canino, 1800
- Jacques Henri Bernardin de Saint-Pierre to Marguerite Charlotte Désirée de Saint-Pierre [née de Pelleporc], 1800–1814
- Richard Brinsley Sheridan to Hester Jane Sheridan [née Ogle], 1800
- Richard Brinsley Sheridan to Willoughby Lacy [the elder], before 1800
- Caroline Lucretia Herschel to Reverend Doctor Nevil Maskelyne, January 1800
- Richard Brinsley Sheridan to Richard Peake, 1800
- père André Morellet, abbé Morellet to Marie Adélaïde Marmontel [née Lerein de Montigny], 1 January 1800
- Jacques Henri Bernardin de Saint-Pierre to André Basile Le Danois de la Soisière, 3 January 1800 [now missing]
- Lady Anne Barnard [née Lindsay] to Henry Dundas, 1st Viscount Melville, 5 January 1800