Imari ware (Japanese: 伊万里焼, Hepburn: Imari-yaki) is a Western term for a brightly-coloured style of Arita ware (有田焼, Arita-yaki) Japanese export porcelain made in the area of Arita, in the former Hizen Province, northwestern Kyūshū. They were exported to Europe in large quantities, especially between the second half of the 17th century and the first half of the 18th century.

Typically Imari ware (in the English use of the term) is decorated in underglaze blue, with red, gold, black for outlines, and sometimes other colours, added in overglaze. In the most characteristic floral designs most of the surface is coloured, with "a tendency to overdecoration that leads to fussiness". The style was so successful that Chinese and European producers began to copy it. Sometimes the different overglaze styles of Kakiemon and Kutani ware are also grouped under Imari ware.

The name derives from the port of Imari, Saga, from which they were shipped to Nagasaki, where the Dutch East India Company and the Chinese had trading outposts. In the West the multi-coloured or "enamelled" wares became known as "Imari ware", and a different group kakiemon, while blue and white wares were called "Arita ware"; in fact the types were often produced at the same kilns. Today, the use of "Imari" as a descriptor has declined, and they are often called Arita wares (or Hizen wares, after the old province). Imari ware was copied in both China and Europe, and has been continuously produced to the present day.

"Early Imari" (shoki imari) is a traditional and somewhat confusing term used for very different wares that were made around Arita before about 1650. The porcelains are generally small and sparsely painted in underglaze blue for the domestic market, but there are also some large green celadon dishes, apparently made for the southeast Asian market, in a porcellaneous stoneware.