The Futagawa Fault is an active fault crossing the Kumamoto region of Kyushu in southwestern Japan, running northeast toward the great Aso volcanic caldera. Together with the adjoining Hinagu Fault, it forms part of the fault network that accommodates the crustal stretching and shearing of central Kyushu.
The fault is chiefly a right-lateral strike-slip structure with a component of normal motion, reflecting the tension and shear affecting Kyushu as the region is pulled apart within the volcanic arc. Its surface trace runs through populated valleys and farmland near Kumamoto city.
The Futagawa Fault ruptured in the main shock of the 2016 Kumamoto earthquake sequence, a magnitude 7.0 event that followed a strong foreshock on the neighbouring Hinagu Fault. The earthquakes produced clear surface ruptures, triggered widespread landslides and damaged Kumamoto Castle, making the fault a landmark case in recent Japanese seismology.