A light source unit for a vehicle includes a light source body, a light guide member that guides and exits the light from the light source body toward a portion of the vehicle to be illuminated, and a cover member housing the light source body and the light guide member. The cover member has an elongated light exit portion through which light from the light guide member is exited to the portion to be illuminated. The light exit portion includes a first light exit portion and at least two second light exit portions arranged along a longitudinal direction of the light exit portion to sandwich the second light exit portion therebetween. Light from the light guide member directly reaches the portion to be illuminated via the first light exit portion and light from the light guide member indirectly reaches the portion to be illuminated via the second light exit portion.