Land art or earth art is a form of art which came to prominence in the late 1960s and 1970s primarily concerned with the natural environment. Materials such as rockss, sticks, soil and so on are often used, and the works frequently exist in the open and are left to change and erode under natural conditions. Particularly large works are sometimes known as earthworks.

Perhaps the best known artist who worked in this genre was the American Robert Smithson. His best known piece, and probably the most famous piece of all land art, is Spiral Jetty (1970), for which Smithson arranged rock, earth and algae so as to form a long (1500 feet) spiral-shape jetty protruding into Great Salt Lake in Utah. How much of the work, if any, is visible is dependent on the fluctuating water levels. Since its creation, the work has been completely covered, and then uncovered again, by water.

Smithson's Gravel Mirror with Cracks and Dust (1968) is an example of land art existing in a gallery space rather than in the natural environment. It consists of a pile of gravel by the side of a partially mirrored gallery wall. In its simplicity of form and concentration on the materials themselves, this and other pieces of land art have an affinity with minimalism. There is also a relationship to Arte Povera in the use of materials traditionally considered "unartistic" or "worthless".

Land artists have tended to be American, with other prominent artists in this field including Alice Aycock, Michael Heizer and James Turrell. Turrell began work in 1972 on possibly the largest piece of land art thus far, reshaping the earth surrounding an extinct volcano in Arizona. Perhaps the most prominent non-American land artists are the British Richard Long and Andy Goldsworthy. Some works by Christo, who is famous for wrapping monuments, buildings and landscapes in fabric, are also sometimes considered to be works of land art.