A cowboy (Spanish vaquero) tends cattle and horses on cattle ranches in North and South America. The cowboy is normally a ranch hand in charge of the horses and/or cattle, as is the wrangler. In addition to ranch work, some cowboys work in and participate in rodeos, and many cowboys work only in the rodeo.

Antecedents
Originally, the word designated a herdsboy who was employed as a cowherd, often on foot (riding requiring skills and investment in horse and equipment rarely available to or entrusted to a boy). Herdswork was often done - more often with sheep or goats - by minors in Antiquity, and still is in various third world cultures; the teenagers of a South African tribe even maintain a specific traditional form of Nguni stick fighting, to defend themselves and their herds.

But in the western culture, herding cattle was rarely left to boys, except as trainees at least approaching manhood, especially as schooling became generalized, and the term became disassociated from the boyish age, at first retaining the notion of low status often implied by 'boy' in professional designations, later being extended to the whole ranch culture.

North America
During the 16th century, they brought the tradition and their horses, the ancestors of the "wild" mustangs, with them to the New World through New Spain (later Mexico). The mustangs are called wild but in reality these are feral animals as they are descended from domestic horses.

Though popularly considered as an American icon, cowboys are a New Hispanic tradition, which originated in the Central States of Mexico, Jalisco and Michoacan, where the Mexican cowboy would eventually be known as a "charro". Historically, the northern parts of Mexico (New Mexico) originally included most of the territory of the American southwest including Texas. In the early 1600s, the Spanish crown, and later independent Mexico, began offering empresario grants in what would later be Texas to US citizens who agreed to become Mexican citizens and convert to Catholicism. In 1821 Stephen F. Austin and his East Coast comrades became the first yankee community speaking Spanish. Following Texas independence in 1836 even more Americans immigrated into Texas and to the empresario ranching areas. Here they were impressed by the Mexican vaquero culture, borrowing vocabulary and attire from their counterparts.

The buckaroo, also a cowboy of the vaquero tradition, developed in California and bordering territories during the Spanish Colonial period. The word Buckaroo, still a common term in the Great Basin and many areas of California and intermittently in the Pacific Northwest, appeared in 1889 in American English, derived (influenced by 'buck', as folk etymology) from bakhara, itself an anglicized alternate since 1827 of 'vaquero', Spanish for cowherd which only entered English one year earlier and itself originates in the Latin vaca 'cow'.

Following the American Civil War, their culture diffused eastward and northward combining with the earlier cowboy tradition that was following the cattle trails out of Texas northward and westward. Sharing the same base, their traditions became indistinguishable with a few regional differences still remaining.

Over time, the cowboys of the American West developed a culture of their own, a blend of frontier and Victorian values. Such hazardous work in isolated conditions bred a tradition of self-dependence and individualism, exemplified in their songs and poetry.

By the 1890s, the open ranges of the Indian Territory were gone and the large cattle drives from Texas to the railheads in Kansas were over. Smaller cattle drives continued at least into the 1940s, with Arizona cattle driven to the railhead at Magdalena, New Mexico. Meanwhile, ranches multiplied all over the developing West, keeping cowboy employment high, if somewhat more settled.

In the 1930s and 1940s, Western movies popularized the cowboy lifestyle but also formed persistent stereotypes. In pop culture, the cowboy and the gunslinger are often associated with one another.

Much has been written about the racial mix of the cowboys in the West, but cowboys ranked low in the social structure of the period and there are no firm figures. The Cattle on a Thousand Hills by John Ambulo in the March 1887 issue of The Overland Monthly states that cowboys are "... of two classes—those recruited from Texas and other States on the eastern slope; and Mexicans, from the south-western region. ...". Census records bear that out. The cowboy occupation undoubtedly appealed to the freedmen following the Civil War. It is estimated that about 15% of all cowboys were of African ancestry—ranging from about 25% on the trail drives out of Texas, to very few on the northern ranges. Similarly, cowboys of Mexican descent also averaged about 15%, but were more common in Texas and the southwest. American Indians also found employment as cowboys early in the history of the West. Many of the early vaqueros were Indians trained to work for the Spanish missions in caring for the mission herds. Following the dissolution of the reservation system around 1900, many of the Indian trade schools also taught ranching skills to Indian youth.