- Dec 1 Sergei Kirov, Russian politician who was Mayor of Leningrad and a friend of Joseph Stalin, assassinated in Leningrad at 48
- Dec 1 Sergey Kirov [Kostrikov], Russian Bolshevik leader and politician (First Secretary (Mayor) of Leningrad, 1926-34), shot to death in his office at 48
- Dec 3 Charles James O'Donnell, Irish politician (b. 1849)
- Dec 6 Duke Charles Michael of Mecklenburg, head of the House of Mecklenburg-Strelitz, dies at 71
- Dec 8 Bernhard Seklas, German pianist, composer, conductor, and pedagogue thought to be the first jazz instructor, dies at 62
- Dec 12 Thorleif Haug, Norwegian Nordic skier (b. 1894)
- Dec 13 Thomas A. Watson, American assistant to Alexander Graham Bell in inventing the telephone, dies at 80 [1]
- Dec 15 Maggie L. Walker, African-American teacher and businesswoman (1st female Bank President), dies at 69
- Dec 17 Edwin Binney, American inventor and businessman (carbon black, 1st dustless white chalk, Crayola crayon), dies at 68 [1]
Assassination
Drug Overdose
Gunshot Wound
Murder
Plane Crash
Suicide