Kanzan Egen (関山慧玄/關山慧玄) (1277–1360) was a Japanese Rinzai Zen Buddhist monk, founder of Myōshin-ji Temple and a principal member of the extant Ōtōkan lineage, from which all modern Rinzai Zen derives. Centuries later, Emperor Meiji conferred the posthumous name Muso Daishi (無相大師) to Kanzan.