Events that occurred on 5 April.
 On Earth
- 1912 - Actor John Le Mesurier is born.
- 1944 - J.R.R. Tolkien writes Letter 59.
- 1981 - The fifth episode of the 1981 radio series of The Lord of the Rings is aired on BBC Radio 4.
- 2001 - Actor Brother Theodore dies of pneumonia.
- 2016 - The Story of Kullervo is published in the USA.