In Old Arizona tells the story of an outlaw in 19th-century Arizona who seeks vindication and a happy ending. Along the way, he encounters various challenges and adventures, including whittling, being wanted by the US Army, and facing vigilantes. The film explores themes of justice, redemption, and the wild west.

The Arizona Kid (Warner Baxter) carries out his mission as a Robin Hood-type bandit while posing as a wealthy and carefree miner. He falls for an eastern girl, Virginia Hoyt (Carole Lombard), accompanied by presumably her brother, Dick Hoyt (Theodore von Eltz), actually her husband. The Kid's mine is raided and two of his friends are killed and he learns that Dick and Virginia are the culprits...

In Arizona a young woman who's being manipulated by an evil businessman is helped by the Cisco Kid who happens to be there on holiday.

The Cisco Kid rides again! This time, he robs a bank to save pretty widow Sally Benton and her ranch. After developing a good relationship with Sally’s children, he risks life and limb in order to save her little one.