A portrait miniature is a miniature portrait painting, usually executed in gouache, watercolor, or enamel. Portrait miniatures developed out of the techniques of the miniatures in illuminated manuscripts, and were popular among 16th-century elites, mainly in England and France, and spread across the rest of Europe from the middle of the 18th century, remaining highly popular until the development of daguerreotypes and photography in the mid-19th century. They were usually intimate gifts given within the family, or by hopeful males in courtship, but some rulers, such as James I of England, gave large numbers as diplomatic or political gifts. They were especially likely to be painted when a family member was going to be absent for significant periods, whether a husband or son going to war or emigrating, or a daughter getting married.

The first miniaturists used watercolour to paint on stretched vellum, or (especially in England) on playing cards trimmed to the shape required. The technique was often called limning (as in Nicolas Hilliard's treatise on the Art of Limming of c. 1600), or painting in little. During the second half of the 17th century, vitreous enamel painted on copper became increasingly popular, especially in France. In the 18th century, miniatures were painted with watercolour on ivory, which had now become relatively cheap. As small in size as 40 mm × 30 mm, portrait miniatures were often fitted into lockets, inside watch-covers or pieces of jewellery so that they could be carried on the person. Others were framed with stands or hung on a wall, or fitted into snuff box covers.