Events that occurred on 4 August
 On Earth
- 1941 - Voice actor Martin Jarvis is born.
- 1953 – J.R.R. Tolkien is angry over the fact that an editor at Allen and Unwin has corrected dwarves to dwarfs, elvish to elfish, further to farther, and worst of all, elven to elfin.
- 1953 - J.R.R. Tolkien writes Letter 138.
- 1965 - J.R.R. Tolkien writes Letter 275.
- 1973 - J.R.R. Tolkien writes Letter 353.
- 1990 - Mythcon XXI at California State University in Long Beach.
- 1995 - Mythcon XXVI in Berkeley, California.
- 2001 - Mythcon XXXII in Berkeley, California.
- 2003 - The Lord of the Rings and Philosophy: One Book to Rule Them All is published.
- 2005 - Omentielva Minya - 1st International Conference on Tolkien's Invented Languages in Stockholm, Sweden.
- 2006 - Mythcon XXXVII at University of Oklahoma, Norman.
- 2007 - Author Timothy J. Wheeler dies.
- 2007 - Mythcon XXXVIII in Berkeley, California.