A lane deviation prevention control device for a vehicle includes a target steering torque calculator, a friction torque estimator, and a friction compensation rate variable controller. The target steering torque calculator calculates target steering torque to be applied to a steering system of an own vehicle in a lane deviation prevention control. The friction torque estimator estimates friction torque of the steering system. The friction compensation rate variable controller performs, on the basis of steering torque produced by a driver's steering operation and on the basis of a traveling state of the own vehicle, a variable control of an addition rate at which the friction torque is added to the target steering torque to compensate friction of the steering system.