The Vardar (Вардар in Slavic Macedonian) or Axios , (Greek Αξιός in ) is a river of the République of Macedonia and Greece. 388 km length, it is the longest river of the République of Macedonia.

The river takes its source with Vrutok, with a few kilometers in the north of Gostivar in Republic of Macedonia. It crosses the town of Skopje, and crosses the north of Greece for jetter in the Aegean Sea in central Macedonia , in the west of Thessalonique. The Greek part of the river 76 kilometers is long.

The river gave its name to the vardháris or vardarec which is a blowing wind along the valley of Vardar and which brings a cold wind to the area of Thessalonique. Vardar also gave its name to the football club of FK Vardar Skopje. Under its Greek name, Axios gave its name to the Greek city of Axioupolis.