The Glogn (Romansh, German: Glenner) is a whitewater river in Graubünden. Glenner was also the name of a district in this area, which was annexed by Surselva District in 2001.

The river rises near the border with Ticino and is surrounded by up to 3100m high mountains. The river flows through the Lumnezia. In Suraua, the Vals Rhine flows into the Glogn. After a few more kilometers, the Glogn flows into the Vorderrhein at Ilanz.