Events that occurred on 20 August
 On Earth
- 1909 - Actor André Morell is born.
- 1943 - Actor Sylvester McCoy is born.
- 1947 - Artist Alan Lee is born.
- 1948 - Actor John Noble is born.
- 1973 - Mythcon 4 in Santa Barbara, California.
- 1981 - The Letters of J.R.R. Tolkien is published.
- 1992 - Tolkien Centenary Conference, a combination of Oxonmoot 1992 and Mythcon 23, at Keble College, Oxford.
- 2000 - Mythcon 31 in Hawaii.
- 2004 - Booster packs of "The Weta Collection", a special set of The Lord of the Rings Trading Card Game, are released.
- 2010 - The Legend of Sigurd and Gudrún is released in Germany.
- 2012 - The Return of the Ring, Tolkien Society conference at Loughborough University, England.