Crestonia (or Crestonice) (Greek: Κρηστωνία) was an ancient region immediately north of Mygdonia. The Echeidorus river, which flowed through Mygdonia into the Thermaic Gulf, had its source in Crestonia. It was partly occupied by a remnant of the Pelasgi, who spoke a different language from their neighbors (Thracians and Paeonians); later the Greeks.
The main towns of Crestonia were Creston (Crestone) and Gallicum (Romanized name). The region, along with Mygdonia, was held by Paeonians for a time, later by Thracians. At the time of the invasion of Xerxes I of Persia, Crestonia was ruled by an independent Thracian prince (Herodotus, 8. 116). By the time of the commencement of the Peloponnesian war, Crestonia had been annexed to the kingdom of Macedonia.