The prairie school or prairie style (in English: Prairie School or Prairie Style) was an architectural style between the turn of the century and the beginning of the century, most common to the Midwest in the United States. The style is generally marked by horizontal lines, flat or with hipped roofs with wide overhangs or eaves "Cover (construction)"), windows grouped in horizontal stripes, in integration with the landscape, solid construction, craftsmanship and discipline in the use of ornamentation. The horizontal lines were intended to evoke and relate to native prairie landscapes. The term "The Prairie School" was not actually used by these architects to describe themselves (e.g., Marion Mahony ("The Chicago Group" uses the phrase), the term was coined by H. Allen Brooks"), one of the architectural historians and one of the first to write extensively about these architects and their works.[1]​.

"The Prairie School" was developed in tune with the ideals and design aesthetics of the Arts & Crafts movement that was pioneered in England by John Ruskin, William Morris, and others. "The Prairie School" shared a harmony of artisanal manufacturing and artisan guilds as a reaction against the new assembly line manufacturing techniques, mass production, which they felt created inferior quality products and dehumanized workers.

"The Prairie School" was also an attempt to develop a Native American architectural style that did not share design elements and aesthetic vocabulary with earlier styles of classical European architecture. Many talented and ambitious young architects had been attracted to the creation of opportunities arising from the Great Chicago Fire of 1871 and which determined the development of the Chicago school of architecture. Chicago's 1893 World's Columbian Exposition was to herald the city's renaissance. But many of the young Midwestern architects of what would become "The Prairie School" were offended by the Greek and Roman classicism of nearly every building built for the fair. In reaction, they sought to create new work in and around Chicago that would showcase a uniquely authentic American modern style, which came to be called Prairie.

The Prairie designation is due to the dominant horizontality of most Prairie-style buildings that echoes the wide, flat expanses and fewer trees of the Midwestern states of the United States. The most famous proponent of the style, Frank Lloyd Wright, promoted an idea of ​​"organic architecture," the overriding principle being that a structure should look as if it grew naturally on the site. Wright also felt that a horizontal orientation was a typically American design motif, in which the younger country had much more open, unrevealed space than in most older, urbanized European countries.