(Θεοδωρίδας), of Sicyon, was one of the ambassadors sent by the Achaeans in B. C. 187, to renew the alliance with Ptolemy Epiphanes, king of Egypt. (Plb. 23.1.) He must have been a man of considerable power and influence in his native country, as at a later period (B. C. 168), we find the two Ptolemies (the sons of Epiphanes), who were then joint rulers of Egypt, applying to him to raise for them 1000 mercenaries. (Id. 29.8.)