Jack Reacher is the fictional protagonist in author Lee Child's series of novels. He is a former military police officer who travels the country to work and investigate suspicious activities. The character first appeared in Child's novel "Killing Floor," which was published in 1997.
Reacher wanders around the United States because he is accustomed to being told where to go by the military. He is a drifter and usually travels by hitchhiking.
Reacher was portrayed by Tom Cruise in a 2012 film based on Child's Reacher novel, "One Shot." The film was released under the title "Jack Reacher." All of Child's Reacher novels have been optioned for film.