Peiraikos, or Piraeicus, was an Ancient Greek painter of uncertain date and location. 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 near the start of his discussion of painting in Book XXXV.112 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.
In the terms of later art history, he painted cabinet paintings of genre subjects. Generally speaking, Pliny seems to derive his information from Varro (116 BC – 27 BC), and Peiraikos may have been contemporary with or somewhat earlier than him, placing the painter at the end of the Hellenistic period or in the early Graeco-Roman period. From his tone, it seems that "Pliny does not know how to judge Piraeicus". Early Modern commentators were to take both approving and disapproving attitudes to later artists compared to him, often assuming that Pliny's meaning followed their own. Peiraikos' subjects may well have been given a comic treatment, but this is not clear. Some equivalent subjects survive in Roman art, especially in shops and shopfronts in Pompeii, small sections of floor mosaics, and in the reliefs of men at work on the Tomb of Eurysaces the Baker in Rome (c. 50-20 BC), but it is interesting to know that such subjects were popular with collectors at the top end of the Roman art market.
Propertius makes a reference to a painter of "small art" in his Elegies, but the surviving text is corrupt, and it is generally thought to intend a reference to the 5th century BC Athenian painter Parrhasios, whose trompe l'oeil painted curtain fooled Xeuxis, an anecdote reported in another passage of Pliny.