Events that occurred on 4 October.
 On Earth
- 1915 - Translator Tore Zetterholm is born.
- 1953 - Actor Chris Fairbank is born.
- 1961 - J.R.R. Tolkien writes Letter 231.
- 1965 - J.R.R. Tolkien writes a letter to Agatha Carew Hunt.
- 1979 - The Jackanory episode "Out of the Frying-Pan and Into the Fire" is aired on the BBC.
- 1999 - Poems from The Hobbit is published.
- 2009 - Ring*Con 2009 in Bonn, Germany.
 In Arda
- T.A. 3018:
- T.A. 2: