Demades (Greek:Δημάδης, c. 380 – 318 BC) was an Athenian orator and demagogue.

Demades was born into a poor family of ancient Paeania and was employed at one time as a common sailor, but he rose to a prominent position at Athens thanks to his eloquence as well as his unscrupulous character. He espoused the cause of Philip II of Macedon in the war against Olynthus, and was thus brought into bitter and lifelong enmity with Demosthenes, whom he at first supported.