The Büyük Menderes River ("Great Meander", historically the Maeander or Meander, from Ancient Greek: Μαίανδρος, Maíandros; Turkish: Büyük Menderes Irmağı), is a river in southwestern Turkey. It rises in west central Turkey near Dinar before flowing west through the Büyük Menderes graben until reaching the Aegean Sea in the proximity of the ancient Ionian city Miletus. The river was well known for its sinuous, curving pattern, and gives its name to the common term used to describe these characteristic bends in rivers.

The river rises in a spring near Dinar and flows to Lake Işıklı. After passing the Adıgüzel Dam and the Cindere Dam, the river flows past Nazilli, Aydın and Söke before it drains into the Aegean Sea.

The Maeander was a celebrated river of Caria in Asia Minor. It appears earliest in the Catalog of Trojans of Homer's Iliad along with Miletus and Mycale.

The river has its sources not far from Celaenae in Phrygia (now Dinar), where it gushed forth in a park of Cyrus. According to some its sources were the same as those of the river Marsyas; but this is irreconcilable with Xenophon, according to whom the sources of the two rivers were only near each other, the Marsyas rising in a royal palace. Others state that the Maeander flowed out of a lake on Mount Aulocrene. William Martin Leake reconciles all these apparently different statements by the remark that both the Maeander and the Marsyas have their origin in the lake on Mount Aulocrene, above Celaenae, but that the issue at different parts of the mountain below the lake.

The Maeander was so celebrated in antiquity for its numerous windings, that its classical name "Maeander" became, and still is, proverbial. Its whole course has a southwesterly direction on the south of the range of Mount Messogis. South of Tripolis it receives the waters of the Lycus, whereby it becomes a river of some importance. Near Carura it passes from Phrygia into Caria, where it flows in its tortuous course through the Maeandrian plain, and finally discharges itself in the Gulf of Icaros (an arm of the Aegean Sea), between the ancient Greek cities Priene and Myus, opposite to the Ionian city of Miletus, from which its mouth is only 10 stadia distant.

The tributaries of the Maeander include the Orgyas, Marsyas, Cludrus, Lethaeus, and Gaeson, in the north; and the Obrimas, Lycus, Harpasus, and a second Marsyas in the south.

The Maeander is a deep river, but not very broad. In many parts its depth equals its breadth and, so, it is navigable only by small craft. It frequently overflows its banks and, as a result of the quantity of mud it deposits at its mouth, the coast has been pushed about 20 or 30 stadia (about 4 to 6 kilometers in modern units) further into the sea and several small islands off the coast have become united with the mainland.

The associated river god was also called Meander, one of the sons of Oceanus and Tethys.

There was a legend about a subterranean connection between the Maeander and the Alpheus River in Elis.

• Küçük Menderes
• Battle of the Meander

• Herodotus (1910). History of Herodotus . Translated by George Rawlinson – via Wikisource.
• Hesiod (1914). Theogony . Translated by Hugh Gerard Evelyn-White – via Wikisource..
• Strabo. H.C. Hamilton; W. Falconer (eds.). "Geography". Tufts University: The Perseus Digital Library.
• Xenophon. Anabasis . Translated by Henry Graham Dakyns – via Wikisource..
• Xenophon, Anabasis, Harvard University Press, Cambridge, Massachusetts; William Heinemann, Ltd., London. 1980. OCLC 10290977. ISBN 0-674-99100-1.
• Thonemann, P., The Maeander Valley: A historical geography from Antiquity to Byzantium (Cambridge, 2011) (Greek Culture in the Roman World Series)

•  This article incorporates text from a publication now in the public domain: Smith, William, ed. (1854–1857). "MAEANDER". Dictionary of Greek and Roman Geography. London: John Murray.

Media related to Büyük Menderes River at Wikimedia Commons