In art, realism is generally the attempt to represent subject-matter truthfully, without artificiality, exaggeration, or speculative or supernatural elements. The term is often used interchangeably with naturalism, although these terms are not necessarily synonymous. Naturalism, as an idea relating to visual representation in Western art, seeks to depict objects with the least possible amount of distortion and is tied to the development of linear perspective and illusionism in Renaissance Europe. Realism, while predicated upon naturalistic representation and a departure from the idealization of earlier academic art, often refers to a specific art historical movement that originated in France in the aftermath of the French Revolution of 1848. With artists like Gustave Courbet capitalizing on the mundane, ugly or sordid, realism was motivated by the renewed interest in the commoner and the rise of leftist politics. The realist painters rejected Romanticism, which had come to dominate French literature and art, with roots in the late 18th century.

In 19th-century Europe, "Naturalism" or the "Naturalist school" was somewhat artificially erected as a term representing a breakaway sub-movement of realism, that attempted (not wholly successfully) to distinguish itself from its parent by its avoidance of politics and social issues, and liked to proclaim a quasi-scientific basis, playing on the sense of "naturalist" as a student of natural history, as the biological sciences were then generally known.

There have been various movements invoking realism in the other arts, such as the opera style of verismo, literary realism, theatrical realism and Italian neorealist cinema.

When used as an adjective, "realistic" (usually related to visual appearance) distinguishes itself from "realist" art that concerns subject matter. Similarly, the term "illusionistic" might be used when referring to the accurate rendering of visual appearances in a composition. In painting, naturalism is the precise, detailed and accurate representation in art of the appearance of scenes and objects. It is also called mimesis or illusionism and became especially marked in European painting in the Early Netherlandish painting of Robert Campin, Jan van Eyck and other artists in the 15th century. In the 19th century, Realism art movement painters such as Gustave Courbet were not especially noted for fully precise and careful depiction of visual appearances; in Courbet's time that was more often a characteristic of academic painting, which very often depicted with great skill and care scenes that were contrived and artificial, or imagined historical scenes.

Realism, or naturalism as a style depicting the unidealized version of the subject, can be used in depicting any type of subject without commitment to treating the typical or the everyday. Despite the general idealism of classical art, this too had classical precedents, which was useful when defending such treatments in the Renaissance and Baroque. Demetrius of Alopece was a 4th-century BCE sculptor whose work (all now lost) was said to prefer realism over ideal beauty, and during the Ancient Roman Republic, politicians preferred a truthful depiction in portraits, though the early emperors favored Greek idealism. Goya's portraits of the Spanish royal family represent a sort of honest, unflattering portrayal of important people.

A recurring trend in Christian art was "realism" that emphasized the humanity of religious figures, above all Christ and his physical sufferings in his Passion. Following trends in devotional literature, this developed in the Late Middle Ages, where some painted wooden sculptures in particular strayed into the grotesque in portraying Christ covered in wounds and blood, with the intention of stimulating the viewer to meditate on the suffering that Christ had undergone on their behalf. These were especially found in Germany and Central Europe. After abating in the Renaissance, similar works re-appeared in the Baroque, especially in Spanish sculpture.

Renaissance theorists opened a debate, which was to last several centuries, as to the correct balance between drawing art from the observation of nature and from idealized forms, typically those found in classical models, or the work of other artists generally. Some admitted the importance of the natural, but many believed it should be idealized to various degrees to include only the beautiful. Leonardo da Vinci was one who championed the pure study of nature and wished to depict the whole range of individual varieties of forms in the human figure and other things. Leon Battista Alberti was an early idealizer, stressing the typical, with others such as Michelangelo supporting the selection of the most beautiful – he refused to make portraits for that reason.

In the 17th century, the debate continued. In Italy, it usually centered on the contrast between the relative "classical-idealism" of the Carracci and the "naturalist" style of the Caravaggisti, or followers of Caravaggio, who painted religious scenes as though set in the back streets of contemporary Italian cities and used "naturalist" as a self-description. Bellori, writing some decades after Caravaggio's early death and no supporter of his style, refers to "Those who glory in the name of naturalists" (naturalisti).