Astymedes a Rhodian of distinction. On the breaking out of the war between the Romans and Perseus (171 BC), he advised his countrymen to side with the former. (Polyb. xxvii. 6. § 3.) After the war, when the Rhodians were threatened with hostilities by the Romans, Astymedes was sent as ambassador to Rome to deprecate their anger. The tenour of his speech on the occasion is censured by Polybius. (xxx. 4, 5; Liv. xlv. 21-25.) Three years afterwards, he was again sent as ambassador to Rome, and succeeded in bringing about an alliance between the Romans and his countrymen. (Polyb. xxxi, 6, 7.) In 153 BC, on the occasion of the war with Crete, we find him appointed admiral, and again sent as ambassador to Rome. (Polyb xxxiii. 14.)