Events that occurred on 30 May.
 On Earth
- 1953 - Actor Colm Meaney is born.
- 1964 - J.R.R. Tolkien writes a letter to Jane T. Sibley.
- 1966 - J.R.R. Tolkien writes a letter to Nancy Smith.
- 1973 - J.R.R. Tolkien writes a letter to Philip Brown.
- 2010 - Guillermo del Toro announces he will no longer direct The Hobbit (film series).
- 2014 - Tolkien in the New Century: Essays in Honor of Tom Shippey is published.
 In Arda
- There are no known events on this day.