Events that occurred on 17 January.
 On Earth
- 1937 - J.R.R. Tolkien writes Letter 10.
- 1964 - J.R.R. Tolkien writes a letter to Mrs. A. Mountfield.
- 1965 - Joan O. Falconer writes a letter to J.R.R. Tolkien.
- 1973 - J.R.R. Tolkien writes a letter to N.J. Kyle.
- 2001 - Tolkien collector Richard E. Blackwelder dies.