- Apr 8 Jan Willem Pieneman, Dutch historical painter (Battle at Waterloo), dies at 73
- Apr 11 Louis Emmanuel Jadin, French composer, dies at 124
- Apr 13 Leopold Gmelin, German chemist (Gmelin's test), dies at 64
- Apr 13 James Iredell, Jr., American politician, dies at 64
- Apr 15 Johann Leopold Fuchs, German composer, dies at 67
- Apr 18 William R. King, American politician (Vice President 1853), dies at 67 one month after his inauguration
- Apr 23 Auguste Laurent, chemist, dies
William Beaumont
Apr 25 William Beaumont, physiologist, dies at 67

William Beaumont
- Apr 28 Ludwig Tieck, German writer, dies at 79