Events that occurred on 13 October.
 On Earth
- 1917 - J.R.R. Tolkien is found unfit for duty for six months, but able to do a desk job.
- 1938 - J.R.R. Tolkien writes Letter 34.
- 1968 - Riddles in the Dark, the third episode of the 1968 radio series of The Hobbit, is aired on BBC Radio.
- 2007 - Ring*Con 2007 in Fulda, Germany.
 In Arda
- T.A. 3018: