- Apr 6 William Strickland, US architect, dies
- Apr 11 Karl Adolph von Basedow, German artist (Ziekte van Basedow), dies at 55
- Apr 15 Arthur Aikin, English scientist & writer (b. 1773)
- Apr 17 Gottlob Wiedebein, German composer, dies at 74
- Apr 18 Joseph Antoni Frantiszek Elsner, Polish composer, dies at 84
- Apr 19 Robert Jameson, Scottish naturalist (b. 1774)
- Apr 22 Nicolás Bravo, Mexican politician & soldier, dies at 67
- Apr 29 Henry Paget, 1st Marquess of Anglesey, English general, dies at 85