- Jan 5 Alfonso Ferrero la Marmora, Italian general and statesman (6th Prime Minister of Italy, 1864-66), dies at 73
- Jan 7 François-Vincent Raspail, French chemist (b. 1794)
Victor Emmanuel II
Jan 9 Victor Emmanuel II, King of Sardinia (1849-61) and Italy (1861-78), dies at 57
- Jan 18 Antoine César Becquerel, French physicist who pioneered the study of electric and luminescent phenomena, dies at 89
- Jan 19 Henri V. Regnault, French physicist and chemist, dies at 67
- Jan 26 Ernst Heinrich Weber, German anatomist and physiologist (one of the founders of experimental psychology), dies at 82