James H. Leavy was an Irish gunfighter in the Old West. He is remembered today by Western historians for participating in at least two instances of a quick draw duel. In his time, Leavy was one of the most notorious gunmen in the Old West known for challenging other gunmen to a duel. He is featured in the book Deadly Dozen, written by author Robert K. DeArment as one of the twelve most underrated gunmen of the 19th century West.

Gunfighters, also called gunslingers, or in the late 19th and early 20th century, gunmen were individuals in the American Old West who gained a reputation of being dangerous with a gun and participated in shootouts. Today, the term "gunslinger" is more or less used to denote someone who is quick on the draw with a handgun, but this can also refer to those armed with rifles and shotguns. The gunfighter is also one of the most popular characters in the Western genre and has appeared in associated films, television shows, video games, and literature.