Events that occurred on 23 March.
 On Earth
- 1917 - Voice actor Hans Conried is born.
- 1963 - Mr. and Mrs. Kloos write a letter to J.R.R. Tolkien.
- 1994 - Donald Swann, composer of The Road Goes Ever On, dies.
- 2003 - The Lord of the Rings: The Two Towers wins two Oscars, out of six nominations, at the 75th Academy Awards.
- 2006 - The Lord of the Rings Musical opens in Toronto.
 In Arda
- T.A. 2510:
- T.A. 3018:
- T.A. 3019: