Phormio is second-century CE play by Terence. The play is an adaptation from a (lost) work of Greek New Comedy. Old Comedy (represented by Aristophanes) takes as its subject matter from the political arena, while the tradition of New Comedy focused more on issues of the family. An archetypal character in the tradition of New Comedy is the trickster. The trickster is often (but not always) a slave.

Terence's play is titled after its protagonist, Phormio. Phormio becomes involved in lives of two young men (Phaedria and Antipho) by means of their slave, Geta, who approaches Phormio in the absence of the boys' fathers (Chremes and Demipho, who are brothers).

Geta explains to Phormio the nature of the boys' troubles in love on the pretext that Phormio is a lawyer. Phormio devises a plot claiming that the poor girl whom Antipho seeks to marry is in fact related to him, and so he must marry her in order to satisfy a law stipulating that a woman without a dowry marry her nearest relative. The father, Demipho, is livid at this proposal, claiming to have no relation to the girl. After some discussion, he resolves to pay the girl in order to dismiss her quietly and avoid marriage. Phormio intercepts this payment, keeps some, and uses part of to buy the desired wife of the other brother, Phaedria.

The dramatic irony is revealed when Chremes, the brother of Demipho and father of Phaedria, realizes that his nephew's impoverished wife is in fact his daughter from a previous marriage to a Lemnian woman (from an island off of Greece). This information is overheard by the slave, Geta, who delivers it to Phormio.

Phormio then bribes the fathers, Chremes and Demipho, to allow the marriages to go through, threatening to tell Chremes's current wife about his previous marriage. She eventually finds out anyway and exacts revenge on her husband by disrespecting him and replacing him as head of household with their son Phaedria.

The play is a satire on social status and gently mocks those concerned with it. Here, the two brothers, Chremes and Demiphon, are determined to have their sons marry respectable and wealthy women, and because of their stubbornness, they are exploited by Phormio.

The play also exhibits features of a "comedy of errors," in which characters' efforts are consistently thwarted owing to events taking an unpredictable turn. This is especially evident in Phormio's discovering the knowledge of Chremes's previous marriage by accident.