The Arys (Kazakh: Арыс [ɑˈrəs]) is a river of southern Kazakhstan and a right tributary of the Syr Darya.

The river begins in the Talas Alatau ridge, and average water flow is 46.6 cubic metres per second (1,650 cu ft/s).

The highest runoff is in April during snow melt, the lowest is in August.

The Arys has been populated by humans since ancient times, and was located to the north of the Silk Road.

Numerous medieval castles, of which the most significant is Otrar, is located in the area.