A vehicle-behavior control apparatus according to an embodiment includes a collision determining unit that determines whether a vehicle collides with an obstacle when the vehicle is decelerated while going straight based on at least a detection result of the obstacle in front of the vehicle and a detection result of a running state of the vehicle in a condition in which wheels are being braked, and a vehicle-behavior control unit that performs at least one of the control of steering rear wheels and the control of giving a difference in braking conditions between the left and right wheels such that the vehicle is decelerated while detouring around the obstacle without steering front wheels when it is determined to collide with the obstacle by the collision determining unit, as one example.