Letter listing for 1770–1779
- Richard Brinsley Sheridan to Thomas Linley, 1775
- [unknown] to Thomas Reid, 1775
- Voltaire confirms the gift of his Württemberg annuity to his family, 1768–1775, before 13 December 1775
- Philippe Louis Maximilien Ernest Marie Ghislain de Sainte-Aldegonde, comte de Sainte-Aldegonde to Michel Paul Guy de Chabanon, January 1775
- William Petty, 1st marquess of Lansdowne [2nd earl of Shelburne] to Doctor Richard Price, c. January 1775
- Voltaire [François Marie Arouet] to Chrétien Guillaume de Lamoignon de Malesherbes, 1 January 1775
- Voltaire [François Marie Arouet] to Conseil de régence de Montbéliard, 1 January 1775
- Voltaire [François Marie Arouet] to Marc Duval, 2 January 1775
- Voltaire [François Marie Arouet] to Frederick II, king of Prussia [the Great], 2 January 1775
- Voltaire [François Marie Arouet] to Étienne Gaspard Perrault de Bruel, 2 January 1775
- James Boswell to William Johnston Temple, 3 January 1775
- Marie Anne de Vichy-Chamrond, marquise Du Deffand [née de Vichy] to Horace Walpole, 4th earl of Orford, 3 January 1775
- père André Morellet, abbé Morellet to William Petty, 1st marquess of Lansdowne [2nd earl of Shelburne], 4 January 1775
- Frederick II, king of Prussia [the Great] to Voltaire [François Marie Arouet], 5 January 1775
- Gustavus III, king of Sweden to Charles XIII, king of Sweden, 6 January 1775
