Antiphon of Rhamnus was an Athenian orator and intellectual active in the late 5th century BCE. He is identified as one of the canonical Ten Attic Orators. Ancient sources describe him as a professional speechwriter, composing forensic orations for others to deliver in Athenian courts. He was also a significant political figure with oligarchic sympathies. According to the historian Thucydides, Antiphon was the chief advisor and strategist behind the oligarchic coup of the Four Hundred in 411 BCE. After the coup's collapse, he was tried for treason, convicted, and executed.

Fifteen speeches survive under his name. Of these, three are considered genuine and complete: Against the Stepmother, The Murder of Herodes, and On the Choreutes. A set of model speeches for hypothetical cases, known as the Tetralogies, is also attributed to him and is important for the study of early rhetorical theory. His works are among the earliest surviving examples of Attic prose. They provide valuable evidence for Athenian legal practices and showcase a sophisticated, methodical approach to constructing arguments, which influenced later rhetorical tradition.

A significant scholarly debate concerns whether Antiphon the Orator is the same person as a writer known as Antiphon the Sophist. Some modern scholars argue they are identical, while ancient sources and others treat them as separate figures. Regardless, Antiphon of Rhamnus remains a foundational figure for understanding the development of rhetoric and the political conflicts in Athens during the Peloponnesian War.