Fresco, the art of painting with watercolors on plaster, while the plaster is still wet, or fresh. 

Fresco painting was known to the ancient Egyptians, Cretans, and Greeks. The Romans also practiced fresco painting. The art experienced a great revival in Italy during the 13th and 14th centuries. In the 15th century the art flourished in Florence. Fresco painting reached its peak in the 16th century, with the supreme achievements of Raphael in the Vatican Palace and with frescoes by Michelangelo in the Vatican's Sistine Chapel.

Fresco painting was widely practiced in Europe in the 18th century, with nobility of style replaced by elegance and illusionistic effects. In the 19th century the art was revived, largely for the embellishment of public buildings.

The most important center for fresco painting in the 20th century has been Mexico. Two Mexican painters in particular, Diego Rivera and José Clemente Orozco, created outstanding frescoes in Mexican government buildings.