Aristotle's Rhetoric (Rhētorikḗ; Ars Rhetorica) is an ancient Greek treatise on the art of persuasion, dating from . The English title varies: typically it is Rhetoric, the Art of Rhetoric, On Rhetoric, or a Treatise on Rhetoric.
Aristotle is credited with developing the basics of a system of rhetoric that "thereafter served as [the] touchstone" of the discipline, influencing the development of rhetorical theory from ancient through modern times. The Rhetoric is regarded by most rhetoricians as "the most important single work on persuasion ever written." Alan G. Gross and Arthur Walzer concur, indicating that, just as Alfred North Whitehead considered all Western philosophy a footnote to Plato, "all subsequent rhetorical theory is but a series of responses to issues raised" by Aristotle's Rhetoric. This is largely a reflection of disciplinary divisions, dating back to Peter Ramus' attacks on Aristotelian rhetoric in the late 16th century and continuing to the present.
Like the other works of Aristotle that have survived from antiquity, the Rhetoric seems not to have been intended for publication, being instead a collection of his students' notes in response to his lectures. The treatise shows the development of Aristotle's thought through two different periods while he was in Athens, and illustrates Aristotle's expansion of the study of rhetoric beyond Plato's early criticism of it in the Gorgias () as immoral, dangerous, and unworthy of serious study. Plato's final dialogue on rhetoric, the Phaedrus (), offered a more moderate view of rhetoric, acknowledging its value in the hands of a true philosopher (the "midwife of the soul") for "winning the soul through discourse". This dialogue offered Aristotle, first a student and then a teacher at Plato's Academy, a more positive starting point for the development of rhetoric as an art worthy of systematic, scientific study.
Aristotle developed the Rhetoric during two periods when he was in Athens, the first, from (when he was second to Plato in the academy); and the second, from (when he was running his own school, the Lyceum).