Art Nouveau is a style encompassing many art forms including painting, glassware, furniture, and architecture. It appeared during the late 19th century, and has influenced art ever since. The style, which takes its name from the French, lieterally means "new art." Art nouveau had incarnations throughout the Western world in the early 20th century, notably Jugendstil in Germany and Scandinavia. It is characterized by the use of stylized organic shapes and dramatic, curving lines. Many of its themes are taken from nature, though presented quite abstractly. The Art Nouveau style has its inspirations in High Victorian style, Roccoco, and Japanese art. It has affinities with the contemporary Pre-Raphaelite, Symbolist, and Arts and Crafts styles.

Art Nouveau architecture and design can be seen in many of the world's cities, perhaps most famously in the Parisian Metro stations. Rennie Mackintosh was a major Art Nouveau architect and furniture designer who worked in Scotland and England. His work provides classic examples of the art nouveau style. Glassware is another important field in which Art Nouveau flourished, notably in the work of Parisians, Lalique and Galle, and the American designer Louis Comfort Tiffany. Tiffany, Lalique, and others also extended the style to jewelry and various decorative arts.

Art Nouveau also appeared in paintings, illustrations, and advertisements of the era. Some of the most well known artists in this style are Aubrey Beardsley, who famously illustrated Oscar Wilde's Salome, Thomas Malory's Le Morte D'Arthur, and the periodical The Yellow Book; Alphonse Mucha, a Czech painter best remembered for his poster designs; Gustav Klimt, a Viennese painter and muralist noted for his heavy use of gold and mosaic-like designs; Henri de Toulouse-Lautrec of Moulin Rouge fame; and Edvard Munch, a Norwegian painter who produced some of the darkest examples of the style in his Frieze of Life series of paintings.

Art Nouveau was succeeded later in the 20th century by the emergent Art Deco style, which incorporated more geometrical shapes and had an even more stylized appearance. However, Art Nouveau still holds somewhat of an influence in certain decorative arts, especially jewelry.