Events that occurred on 20 October.
On Earth
- 1784 – George Tolkien is born.
- 1911 – J.R.R. Tolkien signs a Oxford University visitor's page.
- 1940 - J.R.R. Tolkien writes Letter 40a.
- 1949 – Farmer Giles of Ham is published.
- 1955 – The Return of the King is published.
- 1958 – J.R.R. Tolkien writes a letter to Misses E. Jones and J. Taylor.
- 1958 – Actor Viggo Mortensen is born.
- 1963 - J.R.R. Tolkien writes Letter 249a.
- 1965 – J.R.R. Tolkien writes Letter 278.
- 1965 – J.R.R. Tolkien writes a letter to Timothy J. Wheeler.
- 1968 – Strange Lodgings, the fourth episode of the 1968 radio series of The Hobbit, is aired on BBC Radio.
- 1994 - The War of the Jewels is published in the UK.
- 1997 - Actor John Bell is born.
- 2003 - Tolkien and the Great War is published.
- 2005 – George Sayer, friend of J.R.R. Tolkien, dies.
- 2020 - The Lord of the Rings Online: War of Three Peaks expansion is released.
In Arda
- F.A. 495:
- T.A. 3018:
- Glorfindel, Strider and the four hobbits reach the Ford of Bruinen where they are attacked by Black Riders. Frodo reaches the other riverside but the Riders are cast back by the water, their horses drown and their robes are destroyed.
- Boromir travels towards Rivendell to ask for counsel.