Bisaltia (Greek: Βισαλτία) or Bisaltica was an ancient country which was bordered by Sintice on the north, Crestonia on the west, Mygdonia on the south and was separated by Odomantis on the north-east and Edonis on the south-east by river Strymon.The eponymous inhabitants, known as the Bisaltae, were a Thracian people.
The most important town in Bisaltia was the Greek city of Argilos.
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 by Macedon.
In Roman times, Bisaltia crossed a branch of the via Egnatia, in which the Roman sources (Itineraria) mention four horses change stations : Trinlo (=Tragilos), Graero, Arason (=Arolos) and Euporia.
[2] In various sites of Bisaltia have been found so far several interesting inscriptions of imperial times.