Events that occurred on 23 May.
 On Earth
- 1961 - J.R.R. Tolkien writes a letter to Rayner Unwin.
- 1972 - J.R.R. Tolkien writes Letter 336.
- 1992 - Second day of The Tolkien Phenomenon in Turku, Finland.
- 2008 - The RiffTrax commentary of The Lord of the Rings: The Two Towers is released online.
- 2011 - Update 3: Lost Legends of Eriador, the third update of The Lord of the Rings Online is released.
- 2013 - The Fall of Arthur is published.
 In Arda
- There are no known events for this day.