Decoration in Ottoman architecture takes on several forms, the most prominent of which include tile decoration, painted decoration, and stone carving. Beginning in the 14th century, early Ottoman decoration was largely a continuation of earlier Seljuk styles in Anatolia as well as other predominant styles of decoration found in Islamic art and architecture at the time. Over the course of the next few centuries, a distinctive Ottoman repertoire of motifs evolved, mostly floral motifs, such as rumî, hatayî, and saz styles. Calligraphic inscriptions, most characteristically in a thuluth script, were also a mainstay. From the 18th century onward, this repertoire became increasingly influenced by Western European art and architecture and went as far as directly borrowing techniques and styles from the latter.
Ottoman tiles attained a prominent role in decoration. Starting in the early 15th century, cuerda seca tiles in vivid colours were widely used in various buildings, using mostly vegetal arabesque motifs, of which the most dramatic early example is the Green Mosque and Green Tomb in Bursa (circa 1424). Various examples of tilework from this century seem to show possible Iranian influence and connections to Timurid art. A distinctive style of blue-and-white fritware, influenced by Chinese motifs and often attributed to an early stage of Iznik tilework, is evidenced by the late 15th century and characterizes the early 16th century. Iznik tiles became highly favoured during the rest of the 16th century and reached their artistic peak in the second half of the century. They featured stylized floral and vegetal motifs in blue, white, red, and green colours. The Iznik industry declined by the end of the 17th century, with production of lower-quality tiles shifting to Kütahya. In the early 18th century, a revival of tile art was attempted through the establishment of a new workshop at Tekfursaray in Istanbul, but ultimately the industry faded after this and tile decoration lost its importance.
Painted decoration is a highly visible feature of Ottoman interiors, especially in domes and on upper walls. However, buildings were frequently repainted during later restorations and, as a result, relatively little of the original painted decoration in mosques and palaces has been preserved up to the present day. Surviving examples show that painted designs were related to those of other mediums, including tiles and manuscript decoration, and that floral motifs predominated. Until the 16th century, these motifs remained rather formal and stylized, but from the late 17th century onward they began to change under increasing Western European influence. By the 19th century, European-style motifs were directly incorporated into Ottoman decoration and European techniques such as trompe-l'œil were introduced.
Compared to earlier Seljuk decoration, stone carving occupied a more subtle role in Ottoman architecture. Until the classical period (16th–17th centuries), three-dimensional muqarnas or "stalactite" decoration was the most prominent motif used in entrance portals, niches, columns capitals, and under minaret balconies. Starting in the 18th century, motifs influenced by or borrowed from the European Baroque took over.