The Lamus (Ancient Greek: Λάμος Lamos; Turkish: Lamas Su or Limonlu Çayı) river is a river of ancient Cilicia, now in Mersin Province, Turkey. The river formed the boundary between Cilicia Campestris and Cilicia Trachea, and later between Cilicia Aspera and Cilicia Propria. At its mouth was the city Antiochia Lamotis, earlier Lamos, formerly the capital of the surrounding region, the Lamotis (Alexander Polyhistor cited by Stephanus of Byzantium, Ptolemy Book V, ch. 8, § 6; Strabo, Geography, 14.5.6-7).
During the 9th–10th centuries, the river was the site of several Arab–Byzantine prisoner exchanges.
Coordinates: 36°33′29″N 34°14′50″E / 36.55806°N 34.24722°E