Events that occurred on 21 July.
 On Earth
- 1920 – J.R.R. Tolkien is appointed to Readership in English Language at the University of Leeds.
- 1938 - J.R.R. Tolkien writes a letter to A.F. Colborn.
- 1946 - J.R.R. Tolkien writes Letter 105.
- 1965 - J.R.R. Tolkien writes Letter 273.
- 1967 - J.R.R. Tolkien writes Letter 296.
- 1996 - Actor Wolfe Morris dies.
- 1998 - The Royal Mail published a new set of stamps, "Magical Worlds: Classic Fantasy Books for Children" with art by Peter Malone. One of the stamps features Bilbo and Smaug.
- 2009 - Artist Heinz Edelmann dies.
- 2011 - Light Beyond All Shadow: Religious Experience in Tolkien's Work is published.