Euthydemus I (Greek: Εὐθύδημος Α΄; c. 260 BC – 200/195 BC) was a Greco-Bactrian king in about 230 or 223 BC according to Polybius; he is thought to have originally been a satrap of Sogdiana, who overturned the dynasty of Diodotus of Bactria and became a Greco-Bactrian king. Strabo, on the other hand, correlates his accession with internal Seleucid wars in 223–221 BC.