Abstract: In an apparatus for controlling a headlight of a vehicle, a light from a preceding or oncoming vehicle can be detected without being disturbed by a light reflected on guardrails and the like, or light from a traffic signal, street lights and the like, and the illumination area of the headlight can be suitably adjusted without unnecessary switching of an illumination mode of the headlight. This control is carried out by receiving a light impinging on the front end of the vehicle by a light receiving member divided into a plurality of regions, by carrying out a comparison and discrimination between the light detection signals from the plurality of regions, and based on a result thereof, by selecting an appropriate illumination mode of the headlight.