Events that occurred on 12 July.
 On Earth
- 1918 - J.R.R. Tolkien is readmitted to Brooklands Officers' Hospital, Kingston-upon-Hull by this date.
- 1979 - Mythcon 10 in San Jose, California.
- 1981 - The nineteenth episode of the 1981 radio series of The Lord of the Rings is aired on BBC Radio 4.
- 2002 - Przemyslaw Mroczkowski, scholar and friend of J.R.R. Tolkien, dies.
- 2005 - Der Berggeist is auctioned at Sotheby's.
- 2005 - Tolkien Thing VII in Hohensolms, Hohenahr, Germany.
- 2008 - Tolkien Thing X in Rieneck, Germany.
- 2013 - Mythcon 44 at Michigan State University, East Lansing.