In a legged mobile robot (1), each leg (2) has at least a first joint (16) and a second joint (18, 20) located below the first joint in the gravitational direction, and the actuator that drives the second joint (54, 56) is located at least one of a position same as that of the first joint and a position (28) above the first joint in the gravitational direction. With this, it becomes possible to lighten the weight of the ground-contacting ends of the legs and thereby provide a legged mobile robot enabling reduction of the inertial forces occurring in the legs during moving, particularly during high-speed moving.