December 31 is the last day of the calendar year. It is the 365th day (366th in leap years). It is known best for being the day on which New Years occurs.
- 1898 — Joseph Vacher died.
- 1913 — Louise Vermilya died.
- 1950 — Joseph Nissensohn is born.
- 1960 — John Allen Muhammad is born.
- 1968 — Jeong Du-yeong is born.
- 1986 — Nicolae Vlad is born.
- 2005 — Michael Nicholaou died.
- 2014 — Hayato Imai is apprehended.