When the sheriff pulls Jake Lonergan's (Daniel Craig) wanted poster off the wall, the poster underneath is of director Jon Favreau.
Director Jon Favreau was constantly harassed with demands to shoot or convert the film in 3-D, but he held his ground, claiming Westerns should only be shot on film.
Daniel Craig was chosen because of his distinct likeness to Steve McQueen, who starred in Les 7 mercenaires (1960).
Robert Downey Jr., who worked with director Jon Favreau in the first two Iron Man movies, was set to play Zeke Jackson (a "former Union army gunslinger") but dropped out due to scheduling conflicts when Sherlock Holmes : Jeu d'ombres (2011) was abruptly greenlit. Within a month, the character was re-named Jake Lonergan and re-written to be an outlaw, and Downey was replaced with Daniel Craig.
Daniel Craig recommended Eva Green for the role of Ella after working with her in Casino Royale (2006). Green turned down the role.