Charro, in Mexico, is historically the horseman from the countryside, the Ranchero, who lived and worked in the haciendas and performed all his tasks on horseback, working mainly as vaqueros and caporales, among other jobs. He was renowned for his superb horsemanship, for his skill in handling the lasso, and for his unique costume designed specially for horseback riding. Today, this name is given to someone who practices charreada (similar to a rodeo), considered the national sport of Mexico which maintains traditional rules and regulations in effect from colonial times up to the Mexican Revolution.

The oldest records of the word "charro" date back to the 16th century, and it appears as a word in the Portuguese and Galician languages, with a derogatory meaning, synonymous with “foolish”, “stupid”, “idiot”, “vile”, and “despicable”. The Castilian writer Vicente de Olea compiled the word in his "Vocablos Gallegos Escuros" (Obscure Galician Words) in 1536, where he defined it as "crazy." Meanwhile, the Spanish paremiologist Hernán Núñez defined it as a synonym of "fool" and specified that it was a word of Galician origin in his work "Refranes, o Proverbios en Romance" (1555).

The word was first documented in Spanish until 1627 in the book "Vocabulario de refranes y frases proverbiales" by Gonzalo Correas, based on the texts of Hernán Núñez, also with a derogatory connotation, synonymous with “fool”, “stupid”, “foolish”, or “imbecile”. More than a hundred years later, in 1729, the word would be included in the first dictionary edited and published by the Real Academia Española (RAE), the Diccionario de Autoridades, where it would be defined as a derogatory adjective used to refer to people from the countryside, villages, or rural areas, synonymous with yokel and "rustic":

The uneducated and unpolished person, raised in a place of little policing. In the Court, and in other places, they give this name to any person from the countryside.

In the first edition of the RAE dictionary published in 1780, that definition was maintained, defining the word as: "the rough and rustic person, as villagers tend to be”; but they would add a second meaning for the first time: "adjective that is applied to some things that are too laden with decoration and in bad taste". Thus, the word "charro" was used in the 18th century as an insult or derogatory nickname for country folk, who are considered coarse, rude, and rustic; and for things that overly decorated and in bad taste; synonymous with the English words: “hick”, “bumpkin”, “yokel”, “boor”, “garish”, “gaudy”, “tasteless” and “ridiculous”.

In 1745, the Basque Jesuit, Manuel Larramendi, argued that the word was of Basque origin and that it meant: "vile and despicable thing", and wrote that country people and villagers were called that out of contempt. While the historian and philosopher Antonio de Capmany y Montpalau, argued that the origin of the word was Arabic and that it originally meant "bad of moral malice and of customs" passing on to the Spanish to mean “artistic malice”, thus something "charro" is the same as something gaudy and tasteless.

In Mexico, the word is documented since the late 18th century, originally used as a derogatory term to refer to the Rancheros, the horsemen that inhabited the countryside and haciendas and who carried out all their tasks on horseback, because, as country people, they were perceived as ignorant, crude and unsophisticated. Over time, though, the word charro evolved in Mexico until it was redefined, going from a derogatory adjective to a complimentary noun, synonymous with Ranchero, skilled vaquero and superb horseman. In 1850, the Spanish historian and writer based in Mexico, Niceto de Zamacois, defined what Charro was in Mexico, as:

Charros: gente del campo que se compone mucho para montar á caballo (country people who are very well formed to ride a horse).