Name
- Jefferson, Jacob, Tutor of Queen's College, Oxford1
- Jekyll, Joseph, MP for Calne1
- Jewers, Richard1
- Jones, Leslie Grove, Colonel1
- Kazatschowsky, K-1
- Ker, Charles Henry Bellenden, of Lincoln's Inn1
- King of Bavaria1
- King, John, of Add MS 335431
- King, Peter, Baron Kinq1
- King, Richard, of Add MS 335401
- Kirk, J-1
- Knight, J- A-1
- Koe, J- Herbert1
- La Rochefoucauld, François Alexandre Frédéric, Duc de Liancourt, and (1792) Duc de la Rochefoucauld1
- La Rochefoucauld, Louis Alexandre, Duc de la Rochefoucauld, of Add MS 335411
- Laffert1
- Lambert, James, of Add MS 335431
- Lawrence, William Peach, American Chargé d'Affaires in London1
- Lee, James, of Add MS 335401
- Leech, Elizabeth1