Delftware or Delft pottery, also known as Delft Blue (Dutch: Delfts blauw) or as delf, is a general term now used for Dutch tin-glazed earthenware, a form of faience. Most of it is blue and white pottery, and the city of Delft in the Netherlands was the major centre of production, but the term covers wares with other colours, and made elsewhere. It is also used for similar pottery, English delftware.

Delftware is one of the types of tin-glazed pottery in which a white glaze is applied and usually decorated with metal oxides. In particular, the cobalt oxide is used for its ability to withstand high firing temperatures, allowing it to be applied under this glaze. Cobalt Oxide is also what gives Delftware its trademark blue designs.

Delftware forms part of the worldwide family of blue and white pottery, using variations of the plant-based decoration first developed in 14th-century Chinese porcelain, and in great demand in Europe.

Delftware includes pottery objects of all descriptions, such as plates, vases, figurines and other ornamental forms and tiles. The style originated around 1600, and the most highly regarded period of production is about 1640–1740, but Delftware continues to be produced. In the 17th and 18th centuries the manufacture of Delftware was a major industry, with product exported all over Europe.

The earliest tin-glazed pottery in the Netherlands was made in Antwerp where the Italian potter Guido da Savino settled in 1500, and in the 16th century Italian maiolica was the main influence on decorative styles. The manufacture of painted pottery spread from Antwerp to the northern Netherlands, in particular because of the sack of Antwerp by the Spanish troops in 1576 (the Spanish Fury). Production developed in Middelburg and Haarlem in the 1570s and in Amsterdam in the 1580s. Much of the finer work was produced in Delft, but simple everyday tin-glazed pottery was made in places such as Gouda, Rotterdam, Haarlem, Amsterdam and Dordrecht.

The main period of tin-glaze pottery in the Netherlands was 1640–1740. From about 1640 Delft potters began using personal monograms and distinctive factory marks. The Guild of St Luke, to which painters in all media had to belong, admitted ten master potters in the thirty years between 1610 and 1640, and twenty in the nine years 1651 to 1660. In 1654 a gunpowder explosion in Delft destroyed many breweries and as the brewing industry was in decline, they became available to pottery makers looking for larger premises; some retained the old brewery names, e.g. The Double Tankard, The Young Moors' Head, and The Three Bells.

From about 1615, the potters began to coat their pots completely in white tin glaze instead of covering only the painting surface and coating the rest with clear ceramic glaze. They then began to cover the tin-glaze with clear glaze, which gave depth to the fired surface and smoothness to cobalt blues, ultimately creating a good resemblance to porcelain.

During the Dutch Golden Age, the Dutch East India Company had a lively trade with the East and imported millions of pieces of Chinese porcelain in the early 17th century. The Chinese workmanship and attention to detail impressed many. Only the richest could afford the early imports. Dutch potters did not immediately imitate Chinese porcelain; they began to do so after the death of the Wanli Emperor in 1620, when the supply to Europe was interrupted. "Potters now saw an opportunity to produce a cheap alternative for Chinese porcelain. After much experimenting they managed to make a thin type of earthenware which was covered with a white tin glaze. Although made of low-fired earthenware, it resembled porcelain amazingly well."