- Apr 9 Aristide Farrenc, French flautist, music publisher, and musicologist (Trésor des pianistes), born in Marseilles, France (d. 1865)
- Apr 9 Theobald Boehm, German inventor of the modern flute, born in Munich, Germany (d. 1881)
Matthew C. Perry (1794-1858)
Apr 10 Commodore of the United States Navy who opened Japan to Western influence and trade, born in Newport, Rhode Island
- Apr 11 Edward Everett, American statesman and orator, born in Dorchester, Massachusetts (d. 1865)
- Apr 12 Germinal Pierre Dandelin, Belgian mathematician (geometry), born in Paris (d. 1847)
- Apr 15 Jean Pierre Flourens, French physiologist, born in Maureilhan, France (d. 1867)
- Apr 17 Carl Friedrich Philipp von Martius, German botanist and explorer, born in Erlangen, Germany (d. 1868)
- Apr 23 Wei Yuan, Chinese scholar and geographer of Qing Dynasty, born in Shaoyang, China (d. 1857)