Events that occurred on 20 December.
 On Earth
- 1928 - Father Christmas writes a letter to J.R.R. Tolkien's children.
- 1956 - J.R.R. Tolkien writes a letter to Deirdre Levinson.
- 1971 - Actor Michael Yurchak is born.
- 2002 - Tom Shippey publishes "The Plot Unravels", a review of The Lord of the Rings: The Two Towers in The Times Literary Supplement.