- Apr 1 Arnold Aletrino, Dutch physician, criminologist ,and author (From Life), born in Amsterdam (d. 1916)
- Apr 1 Gaetano Mosca, Italian sociologist (Circulation of Elite), born in Palermo, Kingdom of the Two Sicilies (d. 1941)
- Apr 3 Matthew Ricketts, 1st African American man elected to Nebraska State Legislature, born in Henry County, Kentucky (d. 1917)
- Apr 4 Remy de Gourmont, French poet, born in Bazoches-en-Houlmes, France (d. 1915)
- Apr 15 Émile Durkheim, French sociologist (Division du travail social), born in Épinal, France (d. 1917)
- Apr 19 May Robson [Mary J Robison], Australian actress (Apple Annie), born in Moama, New South Wales, Australia (d. 1942)
- Apr 19 Siegfried Ochs, German composer, born in Frankfurt, Germany (d. 1929)
- Apr 20 Auguste Chapuis, French composer, born in Dampierre-sur-Salon, France (d. 1933)
- Apr 22 Ethel Smyth, English composer, born in Sidcup, Kent (d. 1944)
- Apr 23 Max Planck, German physicist, father of Quantum Physics (Planck Constant, Nobel 1918), born in Kiel, Duchy of Holstein (d. 1947)
- Apr 30 Mary Dimmick Harrison, US First lady (1889-93) as second wife of the 23rd President Benjamin Harrison, born in Honesdale, Pennsylvania (d. 1948)
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