1786 was a common year starting on Sunday (see link for calendar).
- January 8 - Nicholas Biddle, President of the Second Bank of the United States (d. 1844)
- January 12 - Sir Robert Inglis, Bt, English politician (d. 1855)
- January 23 - Auguste de Montferrand, architect (d. 1858)
- February 24 - Wilhelm Grimm, philologist, folklorist (d. 1859)
- March 22 - Joachim Lelewel, Polish nationalist historian (d. 1861)
- June 13 - Winfield Scott, American general and presidential candidate (d. 1866)
- August 17 - David "Davy" Crockett (d. 1836)
- August 25 - Ludwig I, King of Bavaria (d. 1868)
- September 18 - King Christian VIII of Denmark
- September 24 - Charles Bianconi, Italian-Irish entrepreneur.
- November 18/December 18 - Carl Maria von Weber, German composer
- Henry Bishop , English composer
- September 11 - Friedrich Kuhlau, German composer
- December 12 - William L. Marcy, American statesman (d. 1857)
- Balusvami Dikshitar , brother of composer Muttuswami Dikshitar and introducer of the violin into Carnatic music