Wade Hatton (Flynn), is an Irish cowboy, tasked with driving a herd of cattle from Texas to Dodge City, Kansas. Tagging along with the cattle train are gorgeous Abbie (de Havilland) and her alcoholic oaf of a brother, Lee. Lee's drunken antics with a gun eventually force Wade to shoot him, making an enemy out of Abbie, whom Wade had taken a fancy to.
The cattle train arrives in Dodge City, only to find a wretched hive of scum and villainy, full of prostitution and gambling dens and shootouts in the street. Dodge City is currently being ruled by Jeff Surrett, an old enemy of Wade's from days past, the sort of guy who will make a deal for your cattle herd, refuse to pay you, and then shoot you in the back if you complain. The merchants and upper-crust of Dodge City ask Wade to be their sheriff and take back the town from Surrett. Eventually Wade agrees, but Surrett won't go away quietly.
- Amoral Attorney: Surrett's lawyer, who is a partner to his criminal conspiracies and works to help one of Surrett's goons escape from custody.
- Artistic License Geography: The Transcontinental Railroad ran well to the north of Dodge City, through Nebraska rather than Kansas.
- Bar Brawl: One of the all-time Hollywood bar brawls, a five-minute orgy of fisticuffs between ex-Union and ex-Confederate soldiers that completely destroys the interior of Surrett's saloon. Tragically, Olivia de Havilland does not participate.
- The Chanteuse: Ann Sheridan wears a succession of corsets as Ruby, the singer at the Gay Lady Saloon.
- Clean Up the Town: The main plot, as Wade becomes sheriff and works to clean up the Wretched Hive of Dodge City.
- Death of a Child: It's the death of cute little Harry, killed in a carriage accident caused by stampeding horses that were spooked by the constant gunplay in Dodge City, that leads Wade to finally agree to become sheriff.
- Grievous Bottley Harm: One of Wade's buddies gets not one but two bottles bashed over his head during the epic Bar Brawl, and is completely unaffected.
- Have a Gay Old Time: Surrett's club is the Gay Lady Saloon.
- Intrepid Reporter: Clemons, the crusading newspaper editor who leads the opposition to Surrett, and is killed for it.
- Man Versus Machine: The opening sequence has a symbolic little race between a train and a stagecoach. The train wins.
- Mood Whiplash: The supremely silly bar brawl is followed by Surrett and his goons trying to hang Rusty in revenge.
- Moral Guardians: The Pure Prairie League of teetotaling old ladies. Wade's friend Rusty goes to a meeting.
- The Place: Dodge City, Kansas.
- Riding into the Sunset: The ending has Wade and Abbie riding a wagon to Nevada.
- Sequel Hook: Ends with Wade and Abbie riding off to Virginia City, Nevada, where Wade's been offered another job cleaning up a lawless frontier town. Errol Flynn did in fact star in Virginia City the next year, but after de Havilland refused to appear (she was getting sick of playing the Love Interest in Errol Flynn movies), it was made with different characters and set a decade prior to the events of Dodge City.
- "Shut Up" Kiss: Abbie's protests when Wade decides to send her out of town for her own safety are silenced when Wade kisses her forcefully.
- Soft Glass: A cowboy is thrown through a glass window and emerges without a scratch.
- Time Skip: Three years between the opening scenes at the founding of Dodge City and Wade's return in 1872.
- Wretched Hive: A title pronounces Dodge City "the town that knew no ethics but cash and killing." A montage of gun duels and brawls and gambling houses follows. The main street is called "Hell Street". The citizens eventually look to Wade to clean up their town.