A steering assist system for a vehicle includes a turning device, a steering device, a steering sensor and an autopilot device. The steering device is operable to apply a first turning force to the turning device. The steering sensor detects a steering state of the steering device during which the steering device applies the first turning force. The autopilot device automatically navigates the vehicle to a desired heading of the vehicle. The autopilot device includes an actuator and a steering assist control section. The actuator is operable to apply a second turning force to the turning device. The steering assist control section controls the actuator to apply the second turning force to turn the turning device in the same direction that the first turning force is turning the turning device when the steering sensor detects the steering state of the steering device.