The Cisco Kid is a fictional character found in numerous film, radio, television and comic book series based on the fictional Western character created by O. Henry in his 1907 short story "The Caballero's Way", published in Everybody's Magazine, v17, July 1907, as well as in the collection Heart of the West (1907). Originally a murderous criminal in O. Henry's story, the Kid was depicted as a heroic Mexican caballero later in films, radio and television adaptations.

In O. Henry's original story, the character is a 25-year-old desperado in the Texas–Mexico border country who bears little resemblance to later interpretations of the character. He kills for sport and is responsible for at least eighteen deaths. His real name is possibly Goodall ("This hombre they call the Kid—Goodall is his name, ain't it?"); no first name is given in the story. The Kid's mixed-ancestry girlfriend, Tonia Perez, both fears and loves him. When Texas Ranger Lieutenant Sandridge arrives at her home, seeking news of the Cisco Kid, they fall in love. Sandridge begins visiting twice a week. Eventually the Kid visits Tonia's house and finds them together:Ten yards from his hiding-place, in the shade of the jacal, sat his Tonia calmly plaiting a rawhide lariat.

So far she might surely escape condemnation; women have been known, from time to time, to engage in more mischievous occupations. But if all must be told, there is to be added that her head reposed against the broad and comfortable chest of a tall red-and-yellow man, and that his arm was about her, guiding her nimble small fingers that required so many lessons at the intricate six-strand plait.He overhears Tonia tell Sandridge that she heard the Kid was in the area, and that she assumes the Kid will visit her soon. She says she will send Sandridge word of the Kid's whereabouts by Gregorio, "the small son of old Luisa", in time for Sandridge to ride off with a posse, find the Kid and kill him.

Sandridge departs and shortly the Kid appears, pretending he has just arrived. The Kid sends a message to Sandridge through Domingo Sales, who claims that Gregorio is "too ill of a fever to ride". The message says that the Kid has arrived and explains that the Kid has exchanged clothes with Tonia to foil pursuers. Sandridge returns to Tonia's home and sees two figures in the moonlight: one in men's clothing and the other in women's. The one in women's clothing rides away. Assuming this to be Tonia, Sandridge ambushes and shoots the remaining figure. The victim is Tonia, the Kid having tricked Sandridge into killing his girlfriend.