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.

Glogn German: Glenner
Glogn/Glenner above Ilanz
Native name	Glogn (German)
Location
Country	Switzerland
Canton	The Grisons
Cities	Ilanz
Physical characteristics
Source
• location	Alp Scharboda, Piz Terri
• coordinates	46°36′7″N 9°4′8″E / 46.60194°N 9.06889°E / 46.60194; 9.06889
• elevation	2,500 m (8,200 ft)
Mouth
• location	Confluence with Vorderrhein at Ilanz
• coordinates	46°46′36″N 9°12′44″E / 46.77667°N 9.21222°E / 46.77667; 9.21222
• elevation	688 m (2,257 ft)
Length	30.7 km (19.1 mi)
Basin features
Progression	Vorderrhein→ Rhine→ North Sea
Tributaries
• right	Valser Rhine

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. In the upper reaches of the river has cut a deep gorge, which has uncovered black shale in a few places. During the snow melt and after rains the river water is usually dark gray.