To provide a vehicular fog lamp which has a reflector with an optimized reflecting surface satisfying light distribution specifications and attaining suitable visibility and can avoid enlargement.

In the vehicular fog lamp, a reflecting surface R(D) having a width R(D)W as 25% or less of a width RW of the whole compound reflecting surface 3 is arranged on a central section at an upper side of the compound reflecting surface 3 in order to form a light-distribution pattern which is located below an intersection point between a horizontal reference line and a vertical reference line of the light-distribution pattern and at a range of an angle larger than 6° from the horizontal reference line, so that light emitted from a light source 2 is to be reflected at the reflecting surface R(D), and the reflected light is to form the light-distribution pattern.