Events that occurred on 15 October.
 On Earth
- 1844 - Philosopher and author Friedrich Nietzche is born.
- 1931 - J.R.R. Tolkien's poem "Progress in Bimble Town" is published in The Oxford Magazine.
- 1937 - J.R.R. Tolkien writes Letter 17.
- 1959 - J.R.R. Tolkien writes Letter 220.
- 1963 – While dining, J.R.R. Tolkien saves the life of an old lady who nearly choked on a whiting bone.
- 1999 - Author Barbara Strachey dies in Oxford.
- 2007 - Ring*Con 2007 in Fulda, Germany.
- 2009 - Mereth Aderthad XV, or "EstelCon", in Cardona, Spain.
 In Arda
- F.A. 495:
- T.A. 3018: