Gorgias (circa 485-c. 380 bc), Greek rhetorician and Sophistic philosopher (see Sophists). Gorgias was born in Leontini, Sicily. He served as an ambassador to Athens in 427 bc and later settled in Athens to practice and teach the art of rhetoric. As a rhetorician, Gorgias was among the first to introduce cadence into prose and to utilize commonplaces in arguments. He is the title character of Plato's dialogue Gorgias, in which Socrates discusses true and false rhetoric and rhetoric as the art of flattery.

Gorgias's philosophy is a nihilistic one, expressed in three propositions: Nothing exists; if anything does exist, it cannot be known; if anything exists and can be known, it cannot be communicated. The extant works by Gorgias are The Encomium on Helen and The Apology of Palamedes. He died in Thessaly (Thessalia) at the age of 105.