Events that occurred on 21 June.
 On Earth
- 1971 – J.R.R. Tolkien writes a letter to Brian Miller.
- 1981 – The sixteenth episode of the 1981 radio series of The Lord of the Rings is aired on BBC Radio 4.
- 1982 – American actor Benjamin Walker is born.
 In Arda
- There are no known events for this day.