Washi (和紙) is traditional Japanese paper. The term is used to describe paper that uses local fiber, processed by hand and made in the traditional manner. Washi is made using fibers from the inner bark of the gampi tree, the mitsumata shrub (Edgeworthia chrysantha), or the paper mulberry (kōzo) bush. As a Japanese craft, it is registered as a UNESCO intangible cultural heritage.

Washi is generally tougher than ordinary paper made from wood pulp, and is used in many traditional arts. Origami, Shodō, and Ukiyo-e were all produced using washi. Washi was also used to make various everyday goods like clothes, household goods, and toys, as well as vestments and ritual objects for Shinto priests and statues of Buddha. It was even used to make wreaths that were given to winners in the 1998 Winter Paralympics. Washi is also used to repair historically valuable cultural properties, paintings, and books at museums and libraries around the world, such as the Louvre and the Vatican Museums, because of its thinness, pliability, durability over 1000 years because of its low impurities, and high workability to remove it cleanly with moisture.