The majority of William W. Johnstone'sbooks, of which there are over 100,are written in the Western genre;however, he has also written extensively in the thriller and horror genres. Within the Western genre, Johnstone has written a number of series in addition to standalone titles.
Some of his popular Western titles include:
- First Mountain Man
- Last Mountain Man
- Last Gunfighter
- Luke Jensen, Bounty Hunter
- Savage Texas
- Trail West
The author was first published in 1979 and made writing his full-time career from the early 1980s. His background, which informs his contributions to the Western genre, includes employment in the army andas a deputy sheriff.