Folk art describes a wide range of objects that reflect the craft traditions and traditional social values of various social groups. Folk art is generally produced by people who have little or no academic artistic training, nor a desire to emulate "fine art", and use established techniques and styles of a particular region or culture. Along with painting, sculpture, and other decorative art forms, some also consider utilitarian objects such as tools and costume as folk art.

Antique folk art is distinguished from traditional art in that while it is collected today based mostly on its artistic merit; it was never intended as a category to be art for art’s sake. Examples include: weathervanes, old store signs and carved figures, itinerant portraits, carousel horses, fire buckets, painted game boards, cast iron doorstops and many other similar lines of highly collectible "whimsical" antiques.

Characteristically folk art is not influenced by movements in academic or fine art circles, and for the most part, folk art excludes works executed by professional artists and sold as "high art" or "fine art" to the society's art patrons.

The turn of the 21st century saw an increase in work by self-taught folk artists, possibly because of the growing number of retired people with time to spend on new ventures. This 'grassroots art' movement is most visible in the states of Kansas and Wisconsin. The movement has been popularized on public television by the show Rare Visions and Roadside Revelations produced by KCPT in Kansas City, Missouri.

A category of art that overlaps with folk art is naïve art.

Displays, museums and festivals
Folk art is seen in folk art museums and folk art festivals in the United States.

The Museum of International Folk Art in Santa Fe, New Mexico has the largest collection of international folk art in the world. The collection, on permanent exhibit in the museum's Girard Wing, was donated by Alexander Girard.

The term Outsider Art was coined by art critic Roger Cardinal in 1972 as an English synonym for Art Brut (which literally translates as "Raw Art" or "Rough Art"), a label created by French artist Jean Dubuffet to describe art created outside the boundaries of official culture; Dubuffet focused particularly on art by insane asylum inmates.

While Dubuffet's term is quite specific, the English term "Outsider Art" is often applied more broadly, to include certain self-taught or Naïve art makers who were never institutionalized. Typically, those labeled as Outsider Artists have little or no contact with the institutions of the mainstream art world; in many cases, their work is "discovered" only after their deaths. Much Outsider Art illustrates extreme mental states, unconventional ideas, or elaborate fantasy worlds.

Outsider Art has emerged as a successful art marketing category (an annual Outsider Art Fair has taken place in New York since 1992); thus the term is sometimes misapplied as a catch-all marketing label for art created by people outside the "art world" mainstream, regardless of their circumstances or the content of their work.