The Vardar or Axios (Slavic languages Вардар, Greek Αξιός Axios, Latin Axius) is the longest river in the Republic of Macedonia and a major river of Greece. It is 388 kilometres long, and drains an area of around 25,000 km².
The river begins at Vrutok, a few kilometers north of Gostivar in the Republic of Macedonia. It passes through Gostivar, Skopje and into Veles, crosses the Greek border near Gevgelija, Polykastro and Axioupoli ("town on the Axiós"), before flowing into the Aegean Sea in Central Macedonia west of Thessaloniki#Economy in northern Greece.
The Vardar basin includes two-thirds of the territory of the Republic of Macedonia, which some have also called "Vardar Macedonia" after the river.
The valley comprises fertile lands in the Kilkis and Thessaloniki prefectures and Gevgelija and other parts. The river is surrounded by mountains elsewhere. The superhighways Greece Interstate 1 in Greece and M1 and E75 run within the valley along the river's entire length to near Skopje.
The river valley has given its name to the vardháris or vardarec, a northerly prevailing ravine wind which blows down the length of the valley to bring cold conditions to the Thessaloniki area of Greece. It occurs when atmospheric pressure over eastern Europe is higher than over the Aegean Sea, as is often the case in winter. It is somewhat similar to the mistral wind of France.
The origin of the river name is quite obscure and a few theories are in existence:
Dar-ul islam the patriot of islam Dar-ul Erkam the patriot of Erkam, Dar es-salam diyar is pulural form of dar. Diyarbekir or Diyarbakır :in turkish "Bekir'in Diyarı" in inglish "the places of Bekir" or "the partiots of Bekir" or "bekir's dars" .. - * Turks say; Serdar -i Vardar it means ( chief of the vardar)chief of the patriot that the place that should be arrived.
Vardar is also the name of two football (soccer) clubs - one in Skopje and another in Clarkston, Michigan.
"Vardar Ovası, Vardar Ovası; Kazanamadım sıla parası" Turkish Rumelia Songs.