Mount Iizuna (飯縄山,Iizuna-yama), also known as Mount Izuna (飯綱山,Izuna-yama), is a mountain located ten kilometers north-northwest of the heart of Nagano, Nagano Prefecture, Japan. Together with Mount Reisenji (霊仙寺山,Resenji-yama) 1875.0 m, Mount Menō (瑪瑙山,Menō-yama) 1748 m, and others, it forms the Iizuna range. It has an elevation of 1,917 metres. It is one of the "Five Mountains of Northern Shinshu" (北信五岳) that includes: Mount Myoko (妙高山), Mount Kurohime (黒姫山), Mount Togakushi (戸隠山) and Mount Madarao (斑尾山).
This mountain is a sacred site for mountain-based religious sects such as Shugendo, and said to be the home of a tengu named Saburō. According to legend, there was once a strange, edible sand somewhere on the mountain, which the tengu would distribute in times of poor harvest.