Diodotus II (Greek: Διόδοτος Β΄; c. 252 BC – c. 223 BC) was a Greco-Bactrian king from c. 239 BC, son of Diodotus I. He is known for concluding a peace treaty with the Parthian king Arsaces, in order to forestall the Seleucid reconquest of both Parthia and Bactria: