Events that occurred on 31 October.
 On Earth
- 1914 - The Big Four - Tolkien, Wiseman, Smith and Gilson - plan to meet at Cambridge, and all but Tolkien come. Now under the lead of Barnsley and Barrowclough, the T.C.B.S. begins to crumble.
- 1931 - Father Christmas writes a letter to J.R.R. Tolkien's children.
- 1948 - J.R.R. Tolkien writes Letter 117.
- 1954 – "The Hero Is a Hobbit", a review by W.H. Auden of The Fellowship of the Ring, is published.
- 1961 - Director Peter Jackson is born in Pukerua Bay, New Zealand.
- 1964 - The fourth episode of the Princess-serialization of The Hobbit is published.
- 1967 - The Road Goes Ever On is first published in the United States.
- 1970 - Actor Nolan North is born.
- 1974 - Artist Randy Gallegos is born.
- 2001 - Tyalië Tyelelliéva issue 17 is published.
- 2005 - RingCon V at SeaTac, Washington.
- 2010 - Mereth Aderthad XVI, or "EstelCon" of the Spanish Tolkien Society in Valenica, Spain.
 In Arda
- Note: Months of the Shire Calendar only have 30 days, so no events have nor will happen on the 31st.