Peiraikos, or Piraeicus or Peiraeicus, was an Ancient Greek painter of uncertain date and location. He was the chief representative of what is called rhopography (ῥοπογραφία), or the painting of petty subjects, such as still-life. None of his work is known to have survived and he is known only from a brief discussion by the Latin author Pliny the Elder. Pliny's passage comes in the middle of his discussion of painting in Book XXXV of his Natural History, completed about 78 AD:It is well to add an account of the artists who won fame with the brush in painting smaller pictures. Amongst them was Peiraikos. In mastery of his art but few take rank above him, yet by his choice of a path he has perhaps marred his own success, for he followed a humble line, winning however the highest glory that it had to bring. He painted barbers' shops, cobblers' stalls, asses, eatables and similar subjects, earning for himself the name of rhyparographos [painter of dirt/low things]. In these subjects he could give consummate pleasure, selling them for more than other artists received for their large pictures.

Genre painting, a form of genre art, depicts aspects of everyday life by portraying ordinary people engaged in common activities. One common definition of a genre scene is that it shows figures to whom no identity can be attached either individually or collectively, thus distinguishing it from history paintings and portraits. A work would often be considered as a genre work even if it could be shown that the artist had used a known person—a member of his family, say—as a model. In this case it would depend on whether the work was likely to have been intended by the artist to be perceived as a portrait—sometimes a subjective question. The depictions can be realistic, imagined, or romanticized by the artist. Because of their familiar and frequently sentimental subject matter, genre paintings have often proven popular with the bourgeoisie, or middle class.