Cratinus was an Athenian comic playwright of the 5th century BCE, a leading figure in the genre known as Old Comedy. He was an older rival of the more famous Aristophanes. Ancient records indicate he won his first major competition around 450 BCE and remained active until his death, which likely occurred shortly after 423 BCE. Later sources portray him as fond of drink in his later life, a trait he may have humorously acknowledged in his own plays. He achieved significant success, winning a reported nine victories at Athens's dramatic festivals.

His works survive only in fragments and titles from about two dozen plays. His most famous comedy is The Wine-Flask, which won first prize in 423 BCE. This play was a noted example of self-satire, featuring a character representing Cratinus being scolded by his "wife," Comedy, for his drunkenness. Other notable works include The Wealth-Gods, which contained political satire aimed at the statesman Pericles, and The Odysseuses, a mythological parody. According to modern scholars, his style was proverbial for its direct and fierce personal and political invective.

Cratinus is considered one of the three canonical masters of Old Comedy, alongside Aristophanes and Eupolis. Ancient critics like Aristotle later cited him as a prime example of the genre's abrasive, satirical style. His innovative use of mythological burlesque and metatheatrical humor helped establish the conventions of political satire that defined classical Athenian comedy, securing his foundational role in literary history despite the loss of his complete works.