Bisaltia (Greek: Βισαλτία) or Bisaltica was an ancient region extending from the river Strymon and Lake Cercinitis on the east to Crestonia on the west. The eponymous inhabitants, known as the Bisaltae, were a Thracian people. The most important town in Bisaltia was the Greek city of Argilus.[1] There was a river named Bisaltes in the region, which has not been certainly identified.
Bisaltia, along with Crestonia, was ruled by a Thracian prince at the time of the invasion of Xerxes I of Persia, but by the onset of the Peloponnesian War it was annexed to Macedon.
Today, Bisaltia is contained within the Serres prefecture and part of the Thessaloniki prefecture in Greece.