Gakuto Mikumo (三雲 岳斗, Mikumo Gakuto, 1970–) is a Japanese writer of light novel, mystery and science fiction from the Oita Prefecture in Japan. He is a member of the Mystery Writers of Japan and the Honkaku Mystery Writers Club of Japan.He studied the English language at Sophia University, where he graduated. In 1998 Mikumo won silver in the fifth Dengeki Novel Prize with his debut novel, Called Gehenna.