The Ruen Icefall (Bulgarian: ледопад Руен, romanized: ledopad Ruen, IPA: [lɛdoˈpat ˈruɛn]) on Rozhen Peninsula in eastern Livingston Island, South Shetland Islands in Antarctica is situated south of Huntress Glacier, northwest of Prespa Glacier and northeast of Peshtera and Charity Glaciers. It descends towards False Bay from the circus overlooked by Simeon Peak, St. Cyril Peak and St. Methodius Peak in Friesland Ridge, Tangra Mountains.
Ruen is the summit of Osogovo Mountain in south-western Bulgaria.