A lateral motion control apparatus includes a target value obtaining unit, a control amount calculation unit, a steering intent determination unit that determines whether a driver of the vehicle is steering with intent, and a control object control unit that controls the control object so as to control the control object based on the control amount when the driver is not steering with intent, and to stop the control of the control object when the driver is steering with intent. The steering intent determination unit includes a steering operation amount obtaining unit and a threshold value setting unit that sets a threshold value for the steering operation amount based on the target value, and determines whether or not the driver is steering with intent by comparing the magnitude of the steering operation amount with the threshold value.